Look at those stats, talk about a munchkin!
Ability check rules appeared as early as the first issues of Dragon magazine. So while not in the official books, they were around from pretty much the start.
Your right, getting editions mixed up as well as online D&D.
BTW, is your online handle from the great villain Yardiff Bey in Brian Daley's Coramonde duology?
Yes it is, been awhile since someone realized where it came from.
Dont remember if I've read A Tapestry of Magic, I'll have to hunt up a copy.
I think a lot of people are forgetting that stat increases via magical items and magical encounters in adventures were pretty common back then. And seeing as how it took FOREVER to get to level 12 or higher, it stands to reason that all of these PCs had many of their stats increased.
Combine that with the fact that higher statt'd PCs tended to live longer, and it's entirely plausible that no cheating was involved.
My personal experiences would argue strongly that this was not the case. I started playing sometime in the early 80s and Charisma was regularly dumped. If anything, I would point to larger diverse parties as the key element.