Here is the ancient (for this site) thread where I discussed this set some years ago and where some of the information on Old Cardboard comes from...
https://www.net54baseball.com/showthread.php?p=411635
I studied the set quite a bit then and at that time had both the complete Blue and Red backed sets so I could map out the variations between the two sets (there are a lot that vary from major to minor changes).
I thought I had shared that list with the Net54 community via a thread but I cannot find that thread right now...this site is pretty tough to search.
I still have that information (variations) and can share it if people are interested.
-Rhett