To clarify my statement above, the number of packs is just a wild guess. I highly doubt Topps actually damaged or wasted 3 to 5 million checklist cards, but that also doesn't mean they were ever packaged either. Topps would cut the sheets into individual cards and store them in 'cut card cases' which held about 9000 cards, before they were sent to packaging. Many 'cut card cases' from various Topps sets were sold at a discount to card dealers back in the day, and some occasionally turn up on eBay to this day. So even if the checklist cards didn't all make it into packs, most probably made it out of Duryea in some form or another.
Hypothetically, if all 15 million cards were packed with 2 stickers each, that would be 30 million stickers, or about 1,000,000 per title. And, we don't know if there were other printings or just this one. The paperwork below mentions previous job numbers on all three work orders, so all of them are at least a second printing.
For comparison, here are paperwork examples of three (actually four) other sets. Comic Book Heroes Stickers (1975), Good Times (1975), Happy Days (1976) and Marvel Superhero Stickers (1976). Here are the numbers...
Comic Book Heroes Stickers (3rd revision sheet)
23,500 sheets = 6,204,000 stickers = 141,000 complete sets
Good Times stickers
5025 sheets = 1,326,600 stickers = 60,300 complete sets
Happy Day stickers
8,000 sheets = 2,112,000 stickers = 192,000 complete sets
Marvel Superhero Stickers checklists
5,000 sheets = 1,320,000 cards = about 146,667 complete sets with left over cards
Wacky Packages 14th checklists
57,000 sheets = 15,048,000 cards = about 1,368,000 complete sets with left over cards