i am not a variation guy at all. not to say, i don't have extreme respect for folks and their eyes that can find this type of stuff.
...i still cant find waldo.
with that being said, not sure if this is a noted one or not, but i thought something looked off on the 61 koufax card.
it took me a while, but then it hit me. the "A"s in "sandy koufax" are filled in w/ white.
not a scanner fill in, card is in hand.
