I found two of these and trying to identify what year they were made in. I'm attaching some picture. I'm still new to collecting cards (~2 years). I tried to do all my homework, but still couldn't exactly date them.
The code on the ace of space has the letter "C". Based on Lee Asher's table, it could be 2001 or 1981.
It also has a long flap, which I don't know when USPCC stopped using it. If anyone can share that with us.
Also one of the AD cards has "For over 100 years". So i'm not sure what date I should reference.
I will be looking forward to know how to date these cards.