The 50s were an innovative and economic recovery era, after the wide destruction of World War II. The horology world followed the trend, since many of the most iconic watches ever were created in this period.

Among them, we can surely include the Rolex GMT-Master, born from a very practical need.

Back in the days, thanks to Boeing jets rise, the most important airline companies introduced long-distance flights without docks for the first time. Whilst it determined a turning point in terms of speed, the crew faced a new problem, the jet-lag. Scientific studies were conducted to relieve the crew from this phenomenon that caused fatigue and confusion.

Many tests found out that one way to fight the jet-lag was to have an instrument that could simultaneously display home-time and destination-time.

Pan-Am, former US national airline, was one of the first to face this need, entrusting Rolex to create a watch capable to follow these requirements.

The project

Before actually starting the production of the model, Rolex and Pan-Am collaborated for two years to define the project.
The challenge that the maison faced was, first of all, to create a movement capable to display two different time-zones.

The indication of the second time-zone was achieved by an auxiliary hand with arrow-end and red-painted body, that rotates in 24 hours. To read the second time zone was necessary to rotate the bezel on the desired hour or refer to the red hand’s position.
You have an example in the picture below: local time zone 8:18 (classic hands), second time zone 20:18 (red hand).

The name “Gmt Master” was registered the 21st April 1955, giving birth to a glorious line still in production today.

The first version of the Gmt was the reference 6542, with its main characteristics being:

• Absence of crown-guards
• Blue and red Bakelite bezel

Case

The case is a three-pieces Oyster, waterproof up to 50 meters (165 ft). Crown-guards are absent, but we’ll find them in following versions.

The caseback is the classic Rolex produced at the time, with “Montres Rolex S.A.” curved inscription and year of procution’s quadrimester.

Dial

Production started in 1954-55, using dials that we could consider prototypes, with red prints. Among these, the rarest are the ones with both “Gmt Master” and the depth printed in red (three examples known).

Later, 4 gilt galvanic dials were produced until 1959, last year of production

The luminous paint on both dial and hands was manufactured with radium and strontium-90, harmful substances because of their radioactivity. For this reason, in the following years, many original dials were replaced with service tritium dial.

On the lower part, under the “Gmt Master” print, we can find the official chronometer certification print.

The hand set, as in the Submariner, is Mercedes-style.

The date-wheel is “roulette”, alternating black and red numerals, as pictured. By the way, is believed that in the last years of production it was replaced with the classic black-only date-wheel.

Movement

The base on which the 6542’s movement was conceived was the 1030, usually equipping the Turnograph.

The caliber powering the 6542 was the 1036, renamed 1065 and then 1066. It was certified as chronometer and featured a rotor that will be then nicknamed “butterfly” because of its shape.

Bezel

The bakelite bezel on the 6542 is the element that makes this model easy to spot yet incredibly difficult to find all original, due to its extreme fragility.

Bakelite is a plastic (or, better say, a resin) that, thanks to its look and bright colors, gives the watch an immense charme.

(Photo credits: Le Monde Edmond)

To allow the crew for a better time managing, Rolex opted for a two colors bezel: red (daytime) and blue (night hours). These two colors will quickly become the Gmt Master’s symbol, even if other color combinations will be made available.

Radioactivity

To ease the read in the dark, the numbers in the bezel will be filled with the radium and strontium compound. However, this decision created many headaches to Rolex. In the second half of the 50s, studies on radioactivity revealed that these materials (especially strontium) were extremely radioactive and harmful, both for who was wearing the watch and, even more, for employees that assembled it in the factory.

To comply the new regulation, Gmt owners were invited to bring it to their authorized dealer by billboards similar to the ones used to advertise models. They will then send the watch to Geneva. Once the watch reached the facility, bezels were replaced with radiations-free ones.

Non-coeval bezels

As already mentioned, over the years, the majority of bezels were replaced (because of breakage or precautionary). Nowadays, there are 2 kinds of non-coeval bezels:

1. Original Rolex aluminum inserts from later periods
2. “Aftermarket” bakelite inserts (produced by thirds, not by Rolex). The main method used by experts to distinguish between original and aftermarket bezels is to look at the difference in numerals’ graphics.

Other versions

Rolex Gmt Master 6542 yellow gold

So far, we’ve seen the Rolex Gmt 6542 in its classic look. However, there’s a version in gold that’s as charming and even rarer.

The two versions share many common elements, like case and movement.
Main differences are:

• “Burgundy” bakelite bezel
• Burgundy dial
• “Leaf” hands instead of Mercedes
• Applied gold logo on the dial

Rolex Gmt Master 6542 “Albino”

The existence of a white-dial 6542 is still widely debated by collectors.

The story goes that the director of PAN-AM noticed that many executives were wearing GMTs, that were exclusively intended for pilots and crew members. He would have then commissioned Rolex the creation of a very limited quantity of white-dial watches for high rank company’s executives.

The 6542 on the big screen

Collectors and James Bond fans nicknamed this reference “Pussy Galore”, because it was worn by the homonymous Bond Girl in 1964 “Goldfinger”.

The reference 1675

We have seen the birth of the myth, the first GMT, with its special features and various configurations. As you all already know, however, the GMT Master does not stop with the previously discussed ref. 6542. As early as 1959, in fact, ref.6542 was replaced by the new reference 1675, which would remain in production until the late 1970s.

The changes introduced mainly concern:

• Insert: There is a change from the iconic (and problematic) Bakelite insert to a two-tone aluminum one. This solution will prove particularly long-lived, since it will be replaced by the new ceramic only in 2005.
• Case: Just as with the Submariner, the case of the new GMT comes with crown protector straps.
• Caliber: Recall how the 6542 had adopted, in the course of its production, three different designations for the same caliber. The introduction of the new ref. also marks the advent of a totally new movement, namely the 1565.

Reference 1675 is divided into two major productions:

• Specimens with galvanic dial and gold (gilt) graphics.
• Specimens with matte dial and white graphics

Gilt GMT Master

The production of dials with gold graphics corresponds to the first period of life of Ref. 1675, approximately from 1959 to 1967. Such specimens are rarer and more expensive than those with white graphics, both because they were produced in a smaller number of pieces and because the workmanship by which the galvanic effect was achieved is more complex and onerous to make.

What do the terms “galvanic” and “gilt” mean?

Galvanic dials were subject to a rather complex, four-step process.

The first step is to immerse the dial base in a golden bath.
The second is the application of the pad matrices in the part where the various inscriptions were to be.
The third step is a second galvanic bath, this time black, in order to color the entire dial except the part where the dies were.
Lastly, a treatment with glossy paints is performed instead.

The result of this workmanship is very fascinating, as the gilt lettering remains slightly sunken in from the rest of the black surface. This is due to the second bath overlaying all the previously applied gold part.

Case

The new case measures 40 mm, 2 more than that of the 6542.

As mentioned above, the major innovation brought by the new reference is the introduction of protective epaulets, also known as crown guards. In this regard there are two types, both of which can be found in the span of gilt production.

Let’s start with the pointed shoulders or “cornino”: they were adopted from 1959 until the second half of 1964. They turn out to be unmistakable because of the peculiar shape, precisely, of bull horns.

The others are the “normal” or round shoulders. They are the classic crown protector shoulders, introduced after the cornino and always kept that shape from there on.

The caseback features an inscription arrangement common to many other models of the period, with Montres Rolex SA lettering in a bow, and at the bottom, the quarter year of production.

Dial

The dial is the heart of this reference, as much of the watch’s value depends on its originality and condition.

Gilt production dials are distinguished into:

• Closed Minutery: from the beginning of production until 1964. The name comes from the fact that the sexagesimal scale was inscribed in a circle.

• Open minutery: from 1964 until the end of production (and beyond). Disappears the circle delimiting the minutiae.

There are also several graphics, some of which are extremely distinctive and recognizable, for example:

• The very first type of dial, known as “MK1,” immediately jumps out at you. In fact, in place of the new wording “superlative chronometer officially certified,” still stands out the words “officially certified chronometer” (OCC), characteristic of the old movement.

• The dial known as “MK2” is distinguished by the opening inside the crown that is heavily offset to the right. This is why it is referred to by collectors as the “crooked mouthpiece.”

• In the years 62 and 63, dials often carried an underline (called an “underline”) or a dot of luminous material below the 6 o’clock index (called an “exclamation point”). These accouterments were intended to signal less use of radium due to the tightening of laws on the use of radioactive substances.

In 1964 there was another radical change, namely, the final switch from radium to tritium. In those years, in fact, public opinion, as well as the legislative system, became definitively aware of the danger of radioactive substances.

Rolex had to adapt by using tritium as the luminous material of its dials, but it did not end there. In fact, even the amount was limited below 25 curie, as marked on the lower end of the dial (swiss-t <25).

Movement

One of the many changes that ref. 1675 brings with it lies in the movement. In fact, the new caliber 1565 bore the SCOC (superlative chronometer officially certified) designation denoting its precision and reliability.

Do not be alarmed if you find 1560 written in the movement, the “5” simply indicates the presence of the date.

The 1565 is cashed in until 1965, when it is replaced by the more modern 1575(1570 shown in the movement), which will march the 1675 to the end of production.

White graphics Rolex GMT

In 1966 there is a transition from galvanic dials with gold graphics to (opaque) dials with white graphics. The reason for this change is unclear; however, the economic factor seems to be the most popular hypothesis. In fact, the new dial was less expensive and easier to produce.

Unlike gilts, the white lettering is applied on top of black, so they are slightly elevated.

Such processing will remain in vogue until 1984.

Case

The cases are identical to those of the gilt production. The protective shoulders continue to be round ones, a solution that will prove to be extremely long-lived. The caseback inscriptions also remain identical in arrangement, the only change being the disappearance of the quarter in the production year indication.

Dial

Dials with a matte (matte) finish are, to be sure, less rare than galvanic ones but retain a special charm. Again, depending on the period, there are different graphics. Some of them are truly unmistakable and increase the collector’s value of the piece:

• The first dial with white graphics, called “MK1,” is distinguished by the central leg of the Rolex E being the same length as the other two. For this reason this configuration is known as the “Long E.”

• The third or fourth (depending on the classification referred to) type of dial is truly peculiar. In it the pallets are shifted slightly toward the center, creating a unique effect that is much appreciated by collectors. In jargon it is referred to as a “radial” or “mini dial.”

Another difference with the gilts lies in the GMT arrow (the one with the red shaft). In fact, until 1966 the arrowhead was small (“dart”), while later it became larger.

Movement

The 1675 will cash in, until the end of production, the 1575 movement, essentially the same as the first version, introduced in 1965. The only intervention was in 1971, when Rolex equipped the 1575 with a detent function. This meant that the user could interrupt the operation of the mechanism by pulling out the crown.

Bezel

The study of vintage has made great strides in recent years. However, because of the many conflicting opinions, there is still no unambiguous classification for 1675 bezels (either gilt or white graphics).

One example is the so-called “fat fonts.” Some claim they are prerogative of the very early 1675s, while others place them later in production.

Also, since the 1970s, that “Pepsi” is not the only bezel on the 1675s:

• Black bezel: here again there are differing opinions, as some already accept it on the 1675 matt, while others see its introduction concurrent with that of the next ref., namely 16750.

• Blue or “blueberry” bezel: this is where things get complicated, as it is not only debated about the date of relevance but about originality or not! Several collectors claim that the blue bezels never came out of Rolex, but are an aftermarket production. This issue is very intricate, since economic interests come into conflict. For this reason, it will be very difficult to arrive at an absolute truth, especially since Rolex never makes a pronouncement on such diatribes. The fact remains that these bezels have truly stellar selling prices.

Not only steel

Of course, there is a gold version for the 1675 as well, and again there are several configurations to choose from. One example is the dial, known as the “nipple,” because of the applied round gold markers.

In addition to gold, Rolex also produced models in steel and gold, a combination that was very successful in the 1990s. The most iconic and recognizable version of this line is definitely the so-called “tiger’s eye,” which we have already mentioned in the article on nicknames.

It features a two-tone ochre and burgundy bezel, burgundy dial and nipple indexes. The bracelet, also two-tone has a gold center part and steel side parts.

Market

• Gilt: as already mentioned they enjoy higher prices than the later ones, due to the limited production and the charm emanating from the dial. The price can vary greatly, depending on the characteristics of the dial. OCC or underline dials are an example of special configurations, for which collectors are willing to pay a lot.
• White graphics: their price, in recent years, has increased considerably. The most coveted and expensive configurations are “long E” and “radial”.

Beyond individual production there are important general criteria that determine whether we are looking at a mediocre or exceptional piece:

• Kit: the presence of the original kit greatly affects (as much as 100%) the value of the watch.
• Condition: now more than ever, condition is paramount, even at the expense of rarity. It is generally very difficult to find, half a century later, watches that are NOS or never polished. This is especially true for models such as the 1675, i.e., “tool watches,” used for professional purposes.
• Dial: could fall under “condition,” but given its impact on value, I think it is appropriate to treat it separately. Originality is imperative, as a reprinted, retrimmed or even fake dial will really struggle to find a new owner and the price will be greatly affected.

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