The audio from my copy of THE VOICES OF MARVEL flexi-disc is being featured on Boing Boing. Sadly, everyone who is heard on the record is now gone.
https://boingboing.net/2022/07/12/listen-to-a-rare-flexi-disc-record-of-stan-lee-jack-kirby-and-the-voices-of-marvel-from-1964.html
The scripted and rehearsed recording was made in 1965, during Wally Wood’s brief stint working for Stan. Steve Ditko was still at Marvel, but he isn’t heard. Jack Kirby later regretted participating, despite his apparent enthusiasm at the time. Joe Sinnott didn’t return to the Bullpen until a few months later.
I know that one of my audio transfers was used for the video shared on Boing Boing, because of the “thump” heard while artist Don Heck is talking. The audio was captured lovingly and with careful attention to detail, using high-quality audio equipment, as I explained here fifteen years ago.