Just finished the book (hardcover version), and it's WONNNNNNNderful, as G.R. might have shouted.
When I was a kid, I remember Gene starring in a play for several weeks at Chicago's Playboy Theatre. This wasn't mentioned in the "Resume" section of the book. I am not 100% certain, but I think the show was Gypsy, which would have placed it around 1965.
I wanted to go and see it so badly, but I was only around 9 or 10 years old, and it definitely wasn't for kids. I was so disappointed!