Serial Number Range(s): 41xxxxx – 58xxxxx, 31xxxxx – 33xxxxx*
General Notes: The lume plots and variations of font on the Mark 3 are not present in the Mark 4, however, some similarities continue.
- The coronet continues to be tall compared with the early matte dials. It has a smaller base, relative to the width of the top, compared with the Mark 3 and Mark 5. Also, the top of the coronet is not curved but is shaped more like a chevron.
- The serifs on the ‘Rolex’ text are wider and less svelte compared to the Mark 3 and the serifs on ‘Oyster Perpetual’ are no longer preesnt.
- The lower text is most similar to a Mark 2.5 dial.
- Mark 4 vs Mark 5: The Mark 4 and 5 look similar at first glance. The easiest tell between these dials is that, on the Mark 4, the right vertical line in the M of ‘Master’ sits right on top of the middle of the C in ‘Chronometer.’ In the Mark 5, the right vertical line of the M lines up with the right side of the C.
- There seem to be several types of lume mixtures used on this. Generally, the earlier serials seem to have a flat appearance, followed by waffle textured lume in the middle five million serial range, and finally a puffy lume seen in the high fiver millions rage. See examples below.
*the widely accepted serial range is 4.1 to 5.8m, however multiple examples with 3.2 and 3.3m cases have been seen (and even a few with 3.0-3.1m). The serial ranges are guides – not dogma – so while this additional range is questioned by some, it is just that, an estimated range. I personally believe that these earlier watches are okay but my opinion is my own and you should decide for yourself. I will say, Marlon Brando’s rediscovered GMT is a Mark 4 with a 3.24m serial with more provenance than most, so there’s that.