Lets say in 1941 Billy Conn holds on and wins a SD against Joe Louis and opts not to give him an immediate rematch until WWII is over. In this time before joining the effort against the Nazi's Conn fights Lou Nova, Buddy Baer and Abe Simon defending his worlds heavyweight title. How does he do and how much differently would history view him today?
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.
I see Nova being his biggest challenge. He was the most talented of the three as well as the fastest. He was also pretty strong.