For a friend, he's looking for that specific year. Let me know.

 

It's going to be hard

 

Why? I find a lot of the other years

 

Ha, glad you asked....

casebacks marked -69, -71, -74, -76, -78.

so while you can find a watch made in 1973, indeed one with an extract showing a manufacture (or more correctly, a release from the factory) of 1973, Omega did not to my knowledge put a -73 marking in the back.

http://www.speedmaster101.com/145-022-71-74-76-78/

of course just because I have not seen it doesn't mean it hasn't happened, let's see if someone has one!

 

Very interesting. Does that mean they didn't sell their '71 stock until 74?

 

Not at all. They sold/released all the time. I am assuming they simply made watches with parts to hand. When they ran out of -71 casebacks they ordered more, by which time it might have been 1974.

pure speculation!