Let's face it, the Japanese were labeled as copiers (copycats) shortly after WWII and haven't really been able to completely shake it off. Yes, they copy but they usually find ways of making step-wise improvements to the original as time goes on.
They were also quite interested in the work of Dr. Deming shortly after WWII when they were beginning to rebuild their manufacturing capabilities - at a time when US firms had NO interest in his theories of quality improvement. After years of applying his methods (and diligent effort & thought of their own) they learned to surpass US manufacturing! Look @ the auto industry as example.
I'm curious, in your case, if the similarity (Dom to Omega) is only superficial or goes right down to the movement. Have you investigated that?
Anyway, thanks for those nice shots of the 2!
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Seiko Matsuda
The Patron Saint of Seiko Collectors