Hello. Mike “Brain Food” Toft here. I just watched this BBC documentary about R. Crumb from 1987 that’s worth a look. Crumb wrote it himself, so I assume it’s showing him the way he wanted to be shown.
The Confessions of Robert Crumb: A Portrait Scripted by the Underground Comics Legend Himself (1987)
It’s not that much new information if you’ve seen “Crumb” (1994), but still worth checking out. This Open Culture web site looks interesting, too. You’re welcome.