Serial Number Range(s): 41xxxxx-58xxxxx, 32xxxxx-33xxxxx*
Notes: Following the ‘radial dial’ is like having Da Vinci as your older brother – you probably won’t look like a great second act. The interesting fonts of the Mark 3 are not as refined in the Mark 4 but some similarities continue. The coronet continues its tall form but is not as evenly rounded at the top and takes more of a chevroned shape. Within ROLEX – which is slightly more elongated and flatter – the R shape is similar, though not identical, and the wide O is maintained. While the serifs on the ROLEX text are more pronounced, the serifs on the ‘oyster perpetual’ are gone and the lower text is most similar to the Mark 2.5 dial. The easiest tell for this part of the dial is the E’s of the ‘superlative chronometer’ text, where the middle bar is offset toward the top of the letter, unlike the rest of the dial iterations. When comparing to the Mark 5’s, the C of ‘chronometer’ in the Mark 4 is offset to the right of the M in ‘master,’ whereas in the 5’s it lines up under the right part of the M.
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 established serial range on these is the 4.1 to 5.8 million serial range, however several examples with the earlier 3.2 and 3.3 million cases have been seen. As with everything else, assume that the established SN range is correct unless you know where the watch is coming from and trust the seller. The serial range on the Mark 4 is the widest encountered (multiple examples into the high five million range are seen) so I would not be surprised if it totally overlapped the Mark 5.