Re: Louis-Conn history rewrite
Buddy Baer and Abe Simon weighed 250 and 255 at that time. And they were no cakewalks. Conn never fought a relevant fighter above 190 other than Louis. I would have to pick Conn, but would not be surprised by him being defeated by those huge guys. Lou Nova was on a nice run entering the Louis fight, too.
Conn would have picked up one of the best wins in boxing history if your scenario played out. It would elevate his stock enormously, especially if he defended the title to any degree rather than the WWII/collapse of his career which took place.