Pretty easy for Floyd. KO11, or easy UD Canzoneri was feather fisted, he'd never be able to beat Floyd or outbox him. Canzoneri had one hell of a chin though, but it might not be enough for Floyd. He'd be a punching bag in there. Floyd was NOT feather fisted at 35, he had a lot of power at that weight class.
Canzoneri by brutal KO Al Singer Style. Tony was the better fighter and ranks higher pound for pound.
See Floyd-Castillo I. I say Floyd earns a close, controversial decision in a hard fougt, either way kind of fight.