Unlisted Type Cards and "UNC"

[Leon]

At least as early as 1942 there were "official" player checklists. This book has 50+ pages of intricate player lists.
As for issues that are of unknown variety, even though I was lucky enough to find some fairly recently, it's a rare occurence. It could be months or years (or never) before I find anymore. I might chime in some more later. This subject is akin to Teddy Z talking about his beloved T206s. We are still finding new info on Unc sets and refining what we already know. Great topic.