For Topps you have to differentiate between the sets that never made it out to retail and those that did. Two different animals to my mind. 71 Greatest Moments would be a retail set while the 71 Rookie All Stars are actually one of a kind pieces made for a special event. Something like the 1980 coins would be in house mock ups or proofs with only a small handful of each produced. The RAS and Coins were never meant for public consumption. As for the 53 Reprints, DIschley may or may not have suspect info but they were clearly produced in quantities around that of a test issue. I still think a luncheon or testimonial dinner would cover them and like to think maybe they were made for Woody Gelman's retirement dinner (j/k)......he may have crayoned this player notation on the back of my Furillo though, as it's close to his style of handwriting (neater than normal). No clue where the pencilled Pee Wee came from (click the link to see):
http://toppsarchives.blogspot.com/search/label/1972%20%2753%20Topps%20Reprint
I've seen the other errors with a crayoned back as well but don't have scans.