Rick G. can probably tell you for certain but I don't think it's really something that is set in stone. They probably picked up ink pads for the stampers as needed and if someone grabbed a black one instead of a red one they wouldn't have held up production due to that. They may have preferred a particular color during certain years but another color might sneak in from time to time depending on what they had on hand. There is still a bit of uncertainty as to when they stamped the shells (when they made the shell or when they finished it out as a complete drum? although the latter seems the most likely) or even exactly what the date stamps were used for. Ludwig didn't keep any records pertaining to serial numbers so it's doubtful they tracked the date stamps either.

tpick - I have also seen date stamps from 1962 in both red and black. Red was more common, but some black stamps have been recorded.

Have you found a drum stamped on your birthday yet?

(Rick G)

Thanks for the info Rick. The closest I’ve come so far is the day after I was born.