Great match-up! I'm going with Hamsho with a fair ref and fair judges. Fullmer was as dirty as the day is long. And while Hamsho was no Fancy Dan, he had some skills, more pop and could push the pace uncomfortably.
Not too many fights these guys win on boxing boards. Flash and ko artists are the common pick and guys like these are not the guy with his hand raised. Even moreso for Hamsho. I don't see Hamsho having the political pull in his corner to win the rounds against this guy. He'd have to win 75% of the rounds to win a split decision and that's not happening.
The fight would likely take place in Utah or the West Coast and therefore Gene would win. With no home-cooking, Hamsho could certainly turn the trick