Interesting and profound question! I had to check on my own engine before responding. I didn't bother with date codes and wasn't concerned with the cogs.
That's not my answer though: According to Ames Performance Engineering (APE) their catalog shows date coded V belts available for our Birds through 1971; Alt belt #FN692, PS belt FN693 and AC belt (if you need it for that big stock compressor) FN694. My catalog shows they are $38 each. (Probably higher now.)
Hope this helps.
Bill
