I don't think Mosley has enough left to beat Margarito. The Mosley of the early 00s I'd pick to win, but not now.

Mosley doesn't have the stamina at this age to keep up with the ridiculous workrate of Margarito. You see him clinching more nowadays (ex. Cotto fight) for a reason. Mosley has some boxing skills but has always been more of a speedy slugger anyway, who excels in the exchanges, rather than on the backfoot or moving laterally.

Mosley would probably have some moments, especially early on, with his speed, but there wouldn't be enough of those moments throughout the fight.

Margarito UD