Hi,
I am also a bit of a nut regarding errors and variations. I have tried to assemble a master list of them for Bowman (1948-1955) and Topps (1951-1972), and I have this posted on a subpage of my wantlist webpage...
https://sites.google.com/site/richarddingmancards/
Click on links at main page bottom. I try to keep this updated with newer discoveries that emerge and have scoured all available resources for the last few years to condense into this list. If you get a chance to view it, would love to get comments/corrections/additions from anyone else similarly afflicted with the variation bug.
I don't have many to trade at this point, a few '62 greenies (still need one more myself) and a handful of other common variations.
Best to contact me through my email
brightair@msn.com as I don't often get to visit here and am not sure of all site protocols (like, what is bump?).
Richard