Dear
@andyals, I know you'd like it to be a genuine Omega, but it simply isn't.
When you've seen hundreds (or thousands) of Omega watches over many years, the fakes are obvious.
Sometimes immediately (as in your case) and sometimes more difficult to determine due to the methods employed by fake makers (counterfeiters).
Regarding your watch and my observations.
The case shape/proportions in relation to the dial are at odds to Omega design from that era. The crown is also more like one from the 1920/30s or so, not the 1960s.
The dial indexes on a genuine Omega are generally not cut or machined into the metal of the dial, they are either impressed from below, riveted to the dial or simply printed.
The Omega symbol is crudely stamped, and not of a style used in the 1960s, more like earlier periods, possibly 1930s/1940s.
The Seamaster font is incorrect and that lettering style has never been used by Omega in my experience.
The word "OMEGA" has been crudely applied with no clear lines and no serifs expected for fonts of that era.
Omega never produced a watch with 30t2 on the dial.
I would have expected to see "SWISS MADE" on the bottom of the dial, not simply "SWISS".
In addition, if your watch has any markings on the back, it will help to solve the issue, as will a picture of the movement.
Over to you.
Regards
Jim