Mike -
Your post piqued my curiosity about my own photos and who took the photos credited to agencies.
The best one that I have found so far is this one by Herbie Scharfman of Del Rice, Joe Garagiola and Clyde Kluttz.
Few of you have heard of Herbie, but all of you have seen him.
That's him between Ali's legs in the famous Neil Liefer photo.
https://bermangraphics.com/press/leifer.htm
Doug