Topps Wacky Packages 13th Series 1975 Checklist/Puzzle
Vintage Checklists page
13th Series page
Topps Wacky Packages
13th Series 1975
The checklists have nine different images on their reverse sides, which comprise a Beastball puzzle.
13th Series pack
had one checklist, making them quite common.
However the three pieces on the right side are
and are a bit tougher to find.