Sorry to hear this. I am glad that the movie gave him more widespread recognition in his final years. His stuff wasn't always my cup of tea, but I admired the fact that a guy like him (a Joe Blow) could make it as a writer.
"I like your Christ, I do not like your Christians. Your Christians are so unlike your Christ."
I just finished the book a few days ago - it is a long read (540 pages), but it is compelling reading for any wrestling fans from the 80s/90s. As I understand it, he had more than 1500 pages written, but it needed to be whittled down.