Definitely,in my mind. Louis really over the hill in 1951,and Ken would have been too strong for him. Prime for prime would have been a vastly different matter.
I have a book somewhere that states that Joe only had limited use of his right hand by 1951 so was essentially just a shadow of the man who chopped down Max Baer 18 years earlier. Even so bomber Joe lumped up Charles and Marciano's faces with his jab. That version of Joe Louis would have next to no chance against Norton.
I think It boils down to who hit who first with a kill shot. But if i have to pick,well then, kenny gets by that jab, catches him clean and stops him.
Yeah, I have to say that Ken not only likely wins but also has a fair chance of stopping Joe in the later rounds.