I have roughly the same Seamaster although mine is not a De Ville so it supposedly a euro model. Mines from 1963 so I would say yours is definitely from the 60s.

Thank you and I have no idea why I said top left instead of right but thanks for catching my error and thanks for the info.

What’s in the top left corner? Looks like one of the newer Breitlings but it doesn’t look like a Breitling logo.