Just a random thought: Sandy Koufax seems to have been spared by Topps as having none of his images duplicated on his
different cards.
Even his close up head shot on the '55 and '56 are different. A lot of the other players, such as Clemente, Aaron, Mays, Banks all have the same head shots on the '55 and '56 cards.
The only Koufax image on the front of the card that I am aware of that was used twice is the small action picture on the '60 Topps was used as the '61 front.
I realize Koufax's career was relatively short, limiting the chance for duplicates, but it still seems like he lucked out.
You've got players like Willie Mays, where they used the same close-up head shot 3 years in a row ('54-'56) and the same image (just cropped) between '65 and '68 and again between '66 and '69.