Pro Set is well known for its early ability to correct, change, or modify cards as a need may arise. Some changes were from a regular release card to traded banners added as in the Jim McMahon card. In 1989 Pro Set released their football card set in series. The series III assortment is notorious for its share of super rare variations. It wasn’t until several years later that variation c was discovered and documented. However, it took me 15 years to ever see one. A couple of years ago, an eBayer had about 50 of these and they were selling fast. I bought one. Here are the scans.
Variation a Front: No Traded Back: No “See also” line
Variation b Front: Traded Back: “See also” line
Variation c Front: Traded Back: No “See also” line
1989 Pro Set Football Series III