Serial Number Range(s): 41xxxxx – 58xxxxx, 30xxxxx – 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 3.0 to 3.3m case serials have been seen. All serial ranges are approximations and some collectors do not agree with this early range. I personally believe that these earlier serials are legitimate but please consider the watch in front of you and the trustworthiness of the seller. Of note, Marlon Brando’s rediscovered GMT is a Mark 4 with a 3.24m serial with more provenance than most, so there’s that.