I just started reading the book, and so far its kinda interesting, but loaded with errors. Today I read about the reference to the TV show "The Untouchables". The book mentioned it was on the radio. It was never on the radio. The series started as a sort of mini series, and was so popular they made it into a weekly series. I think the author was thinking of the radio series called GangBusters"

Fredo being gay/bi is an interesting twist to the character. I found it to be in line with his character. He was basically a weak person, that just like to have fun and pleasure without much regards to morality.