Thanks everyone. I do not see an assembly date stamped into the pad next to the valve outlet on the top of my box.

Tom - I was hoping to find a box with a date in the October range since my car is a B21 SPD. Not sure if you have one that’s a little later.

Which brings me to another question: If a box was cast in Oct-Dec, how did they represent the 2-digit month on the box? It doesn't appear as though there's enough room for a 2-digit month, 2-digit day, and 1-digit year (5 digits total). It looks like they only have room for 4 digits. Did they switch to a letter code for the month, like A289, as an example for Oct 28th 1969?

Rob