I think it would have been a split decision like the Barkley fight except Bennie blocked more punches than Iran did so it might also be a bit like the Sraling v Nunn fight, Nunn won both and would probably edge this one too whilst missing most of his shots, he wasn`t a very economical puncher.
Nunn fairly easily. Briscoe is one of the all-time gatekeepers, it's true, but his ledger against real good opposition is almost all losses.
Nunn in his prime probably beats aging M.Hagler. He beats any version of Briscoe. Theirs to many too's for Briscoe here Nunn's too fast, too tall, a southpaw, had good pop in his shots, and was well schooled. Briscoe had the "punchers chance" but more than likely Nunn's wins a easy unanimous dec.
Nunn has a bad style for Briscoe- tall slick southpaw. Early Nunn shuts Briscoe down and pretty easily. Briscoe won't be able to cope with Nunns speed.
Since Nunn is still alive, I count him as fighting today. Therefore, by the Classic Forum Theorem, Briscoe knocks Nunn out of the ring.
Nunn should be able to win this. Briscoe would be competitive and have his moments but the most likely outcome is a clear Nunn decision