great uncle. you've just got good guide on speedmaster101 up there. two important clues you can initially check thru a trusted friend-watch repair shop near you - the serial no. and caseback marking references, to confirm your suspicion. you might have an interesting piece and thereafter, omega s.a. or speedmaster expert can help you from there. though there's a sign of refinishing on caseback. ignore any private message for now since you made it a public post.