Prime Norton survives against 1991 Foreman Foreman was able to cut the ring quite well, but I have the impression that Kenny would be too fast and movible to catch. Unless Kenny does something stupid "ala Moorer", he should last the distance, and very probably win by points
Foreman was a puncher and the very notion of such might be enough to still get the job done against Norton.....who seemed to unravel with big punchers at the top level.
I think the best strategy for beating Norton was to get him on the back foot (easier said than done) and the 1974 Foreman famously did this with ease. In 1991, Foreman was just as powerful and I think stronger. He would still break down Norton within a few rounds, although he would almost certainly take more punishment in doing it.
...I have no idea. Foreman didn't knock out any Norton-caliber heavies at that age but he did hurt Evander and he did knockout Moorer, who I think is highly underrated but Moorer and Holy both turned pro at light HW. Evander was probably at his best at CW and Moorer at LHW.
1991 Foreman was heavily reliant on the jab, and Kenny did well with jabbers -- but kenny still liked fighting on the front-foot, and old Foreman still had a mean uppercut. I'd favor old George, still, though Kenny dishes out plenty of hooks to the dome.