Very interesting Jeff, thanks.

Does anyone have a comment on the two different bezel ridge styles?

As you can see below, there are two styles of ridges, one with much finer pitch on the ridges.

Obvious conclusion is the different ridge styles corresponded to earlier or later models but it is not obvious. Check out Jeff's comparison and you can see the close pitch style on early and late versions.

The close pitch ridges on the right are on a later fluted pusher / red insert hands version.
The left hand side bezel is from a transistional fluted pusher /smooth hands version.

The two watches are shown on the link below (I dont know how to post two image URLs)