I would question a prime Foreman's mentality. The losses to Ali and Young don't convince me at all that he was mentally tougher than Tyson at that time. Douglas did not beat a prime Tyson. Norton did not beat a prime Ali.
The course of the fight would be something in between Mike Tyson vs Trevor Berbick and Ken Norton vs George Foreman.
Tyson wins by ko, too fast and too explosive . Kenny with his left low would be a disaster against a prime Tyson.
Norton could never fight a puncher. His crossed armed defense was no defense at all. Tyson destroys him.
I find this a bit ridiculous. And I think it may have something to do with the Larry Holmes cult wanting to prop up Norton. He wasn't in Tyson's class, and would have been wiped out.
He was a very good fighter, he just doesn't match up well with Mike at all. I could picture him giving Holyfield hell for example.
He was very good but limited. He was good against boxers, but not at all against punchers. Tyson was had the best hand-speed to power ratio ever. Ken wouldn't see it coming.
Tyson would be a stylistic disaster for Norton. Faster, more power, better combination puncher, sturdier, better defense. Fight wouldn't go more than 3 rounds.
While I think Nortons chin is over criticized, Tyson KO1. Similar to Norton Shavers, except maybe last a little bit longer, if we are talking prime for prime.