Moved to new thread... The watch appears to be a DeVille Prestige Automatic Circa 1990s with a Calibre 1120 movement, though these are widely faked due to their simplicity of design and common movement so it'd be worth seeing the movement inside to tell if its the genuine article or not.
if you have an old omega, why not post it in the VINTAGE Omega section? if it really has a 1120 mov. than that is already very good, as that is the same one found in the seamaster pro 300's