1655 dial/bezel pairings

[Dan S]

I am trying to learn more about 1655s, and I think I am getting better at identifying the various generations of dial and bezel. However, I'm not entirely clear on which dials may have been originally paired with which bezels. Obviously, one would expect to see Mk1/Mk1, Mk2/Mk2 pairs, etc. But I'd expect that some other combinations were probably also factory correct. I think I have read most of the reference material readily available on the internet, but I'm not sure this issue has been comprehensively addressed, and I'd love to pick the brains of more knowledgeable forum members.

To make this concrete, here is a watch currently for sale on eBay. I realize it has other issues, but I mainly wanted to focus on the dial/bezel pair. I believe that this is a Mk2 dial and Mk4 bezel, according to the naming conventions I have been following on forums. At first I thought it might have been a service bezel, but after looking very closely, I'm pretty sure it is a Mk4. So, at first glance, this seems like a mis-match, but is it? The serial is 4.0M. Is that too early for a Mk4 bezel? This is the type of question I'd like to be able to answer for myself.

I would be delighted if this particular example could lead to a broader discussion about the serial number timelines of 1655 dials and bezels.