"I wonder if any of those copies have been sold/resold or if they're in someone's collection"
I sold them to some guy in his early 20s from Flushing, New York, who drove to my house. He gave me money orders for the $550, and I never ever learned his name (he wasn't Robert Bell, a famous early dealer I was friends with, or anyone else I knew).
He may have sold the books individually soon after, but the romantic in me likes to think he still has them!
Just as well I sold them. What would I do with 20 million?
Bruce