Rex Layne was a very good and strong boxer. I don't think Galento was near Rex's level. If we look at his stats, we can see that Galento won mainly against weak and much lighter opponents. His biggest win was against Lou Nova in one of the dirtiest fights ever (Galento should have been disqualified). He also won against good but nothing special opponents like Al Ettore, Leroy Haynes and Nathan Mann and this is pretty much everything that he achieved in his career. He lost all of his fights against the top contenders. He lost against Arturo Godoy (twice), Max Baer, Buddy Baer, Ernie Schaaf and was badly beaten and stopped by Al Gainer (168lbs). I think Rex Layne will bathered Galento throughout the fight and won by TKO in R7 or R8.