i saw WARP in Chicago as a kid back then myself.... I loved it as a 13 year old! They had a bunch of Neal's art as posters and hangings around the theater. I spent as much time looking at that as I did the play itself.
I do remember there was a very brief nude scene...somewhat hidden by a guaze drapery had made my parents VERY uncomfortable sitting with their 13 year old son!!
Volkes has a very nice style about him in both his artwork in his interpersonal interactions. I had a cool chat with him a few years back and he did an impressive watercolor sketch (Though it was very detailed) of the protagonist from his Wicked West graphic novel.