Ya, not a lot has been written about Hy Larner. I believe in the 1983 OC chart he is listed as a soldier under Joe Ferriola's crew. Corbitt makes him out to be some sort of boss which I have a hard time believing.
In the book about the Dianne Masters murder they discuss how corrupt and what a piece of shit Corbitt really is. He fails to talk about all the extortions, arsons and other cover-ups he did in his own book.
Corbitt died about a year or two after his book came out. I heard him interviewed on the radio promoting his book and he still claims Spilotro killed Giancana. I have no clue on why a lot of people think Spilotro did the job when it was clear that Butch Blasi did it.