Duran circa Hagler fight gives him some trouble, has the skills to be competetive, but Toney wins, IMO... He's the bigger, stronger guy... Hagler basically dominated the last few rounds once he stopped dicking around and became aggressive... Toney isn't as good going forward as Hagler by a long shot, but against a guy who, while slick and defensively sharp, is not a guy who really does well at long-range on the backfoot, I don't see that this deficiency can be adequately exposed. Toney wins it with harder punching and strength Toney UD
It'd probably be a beautiful fight to watch but in the end pretty one sided as it went on. I think Toney would eventually knock him out.
But again, this is really at least a superiddleweight fight. Make Toney weigh 160 6 hours before the fight and he might well be KO'd from the thrill of Duran's thick, luscious hair brushing across his shoulders.