...which probably was not a brilliant idea as selling the Desert Shield and getting a nice collection of other amphibians would have been preferable...I guess a previous owner didn't want a dial with the US flag on anymore so they changed it for a Scuba Dude, that's why the watch still has the original black painted hands from the Desert Shield (should be chrome on this dial)...
I think this is the right track. Plenty of export models, with the catching onion dome caseback, had ordinary Cyrillic dials, because there are so few Latin dials. While I cannot say for sure this isn't a franken, it may also be just an ordinary export model.There was a time when latinized dials and casebacks where more frequent than Cyrillic ones (but they always matched, unlike this example).
I may be wrong but I think I recall seeing similar casebacks on Italian Vostoks (Vostoks made for the Italian market or modified by Italian importers, during the Italian craze for everything Soviet), so maybe this caseback made its way to a Cyrillic dialed watch?
Very interesting nevertheless!