Topps Wacky Packages
4th Series 1973 Checklist Puzzle
This series has two different checklists because when they pulled Choke Wagon and Bum Chex and replaced them with Windhex and Mess Clairoil, they also reprinted the checklist.
There was a time when the checklists still had the Bum and Choke checklist, but the boxes had neither of them, nor the replacements. That must have driven some kids crazy.
As a result, the Bum/Choke checklists are quite a bit harder to find than the Windhex/Clairoil versions. But nowhere near as difficult as the Bum and Choke stickers themselves.
Every pack had one checklist, making them quite common.
However the three pieces on the right side are short-printed and are a bit tougher to find.