I think that a fight between these two in their primes at either 160 or 168 would end up being the same result, with Nigel Benn winning in a much tougher competetive fight over Iran Barkely with the match going into the late rounds with Benn "The Dark Destroyer" registering a tko victory in the 10th or 11th rounds and almost in a worse case scenario like the almost fatal Benn-Gerald McCullen knockout affair in '95, minus any serious career ending injury of course. Or in a better scenario like Barkely's first title(Shot)fight against Sumbu Kalambay in '87 which went the full 15-round distance but except this version of Benn-Barkley would be a little bit more exciting with Benn winning a fairly close but convincing decision over "Blade" Barkley like Kalmbay did then.
I see Barkley beating Benn if it goes 3 rounds or more. Benn's shot is to catch him cold, he can't let Iran get warmed up, or the fight would never end (so to speak) and he'd be ground down. Benn was extremely explosive early doors of course.
Remember, Barkley was A LOT bigger than Benn and had a great counter left hook to counter Nigel's wide right hook.
I think it was 50/50 first time round when Nigel won and I think it would be a 50/50 fight at any time.