You are dead on about the '72 Aaron, that's why I recently picked up these two guys:
72aaron.jpg
The corners are a bit iffy, but I wanted a centered version of this sucker, so I'm happy just to have them.
Some stupidly-tough-to-find-centered HOF'er cards from that era (that immediately come to mind) are 1969 Banks, 1969 Clemente, 1970 Aaron and 1971 Brock.