I am having a discussion about the various styles of dial on the early 1680s. One argument is that the very first dials can be distinguished by the fact that the 6s on 660 are closed. Another argument is that the Mk1 dial is typified by the fact that the F on 660FT is shorter and that the word "Submariner" is slightly narrower than the 200m= 660FT underneath it. I am curious what others believe is the Mk1 dial traits? I do wonder if there actually is such a thing as a Mk1 dial on this watch as it seems Rolex used more than one dial-maker...so plausible that two different types of dial were made at the outset. Thoughts?