I am looking to buy a Speedmaster case. It is one of the older models, from 1966 to present, not one of the earlier straight lug models. My question is...

Without a movement, caseback or bezel to help determine what year the case was made, are there any differences in the cases themselves that could help to date code them?

From what I can tell they are essentially identical from 1966-1986. I have read that the lugs are slightly longer on modern Speedmasters but, in those 20 years or so, are there any differences in the case? THX

 

This site is a great reference for figuring out the differences between models: http://www.speedmaster101.com/145-022-6869-transitional/

It seems like there is not much variation in the cases though. It could be tricky to determine the year based on the case alone.

 

I believe there was a difference in where the Springbar holes are located. This is why certain end links, such as 808 need to be filed down to fit older cases. Probably not much use in aging a specific case though