I found a recent compilation video about Louis that shows Joe knocking down, perhaps out, a black fighter who looks a lot like Charles. It's an older Louis but I certainly have never seen this one before.
No this was an older Louis not the Louis of WWII. Ill see if I can post it later. All it shows is a couple of overhand rights and the opponent falls on his butt to the canvas. Def not an exhibition from what I saw.
