I knew John Money, and studied under him repeatedly between 1978 and 1983. He was brilliant, controversial, and also, unfortunately, quite wrong in some areas. Particularly about his idea that gender identity could be molded and shaped by therapy early on. So don’t take his work as gospel.
Even so, he made excellent points about paraphilias, and he was an early advocate of having those with gender identity noncomformity issues be considered for treatment with hormones and surgery.