Anybody else spotted an F300 with this bezel or is it just aftermarket? Looks dam good either way.

 

Looks OK but no have never seen one like that and would suspect it's just a substitute bezel. I think the bezels for these were very prone to wear.

Here is one with correct bezel.... https://omegaforums.net/threads/fs-immaculate-full-set-f300-geneve-with-rotating-bezel.76197/

 

As noted above, that has a replacement bezel. This is what the similar model without bezel looks like: