While I don't have any "motivation cards" per se, I do love old manager/coach/executive cards. The first vintage card I ever bought was a 1954 Topps Heinie Manush coach card. I guess it stuck with me.
One I want to own someday is this one (even though Huggins wasn't a manager yet):
It reminds me of this one, my favorite from the '51 Bowman set:
The first vintage set I completed was '56 Topps and I loved this Mayo Smith card, plus the set had Warren Giles & William Harridge cards:
