If Chris Mautner's "Collect This Now!" series was called "Finish This Now!" then he probably would have already covered writer Alan Moore and artist Bill Sienkiewicz's Big Numbers. Two issues saw publication in 1990, with the other ten issues never seeing the light of day (as detailed on the book's Wikipedia page).
Well, now lettered artwork of the third issue has surfaced thanks to the magic of the internet and eBay. Pádraig O Méalóid, aka LiveJournal user glycon, details how he came to possess Xeroxed copies of the third issue, which were listed on the auction site earlier this year. Glycon checked with Alan Moore before publishing the pages on the web:
In any case, everything I know leads me to believe that this is a copy of the unpublished third issue of Big Numbers, and I genuinely didn't believe it existed, and certainly never expected to actually see a copy, led alone own one. Even Alan Moore doesn't have a copy, to the very best of my knowledge, which in this case is considerable, as I decided to specifically ask his permission before I posted this here. He is happy for it to be made available to the world, so here it is.
I know I have the first two issues somewhere in my collection ... time to start digging!