Urban Fantasy discussion

Does anyone remember this literary gem? It's written by Baldwin Hills, which has to be in the top ten pretentious pen names. I bought the cheap paperback when I was a kid in 1971 and the cover says: NOW A MAJOR FILM. I found that surprising, as most of the story revolves around Simon's huge willy, with its pentagram tattoo, which he uses both on various ladies and as a wand in his occult rituals. Looking at IMDB, I see it was actually released, but I'm guessing without the fanfare that surrounds, say, Avengers, Age of Ultron. It never appeared at my cinema and I've never spotted it on TV. Has anyone read it or seen it?