Appeal of pre-war minor league issues?

[Exhibitman]

My take is a little different since I only collect HOFers and popular MLB players in the minor league sets. I like them because they often represent the first or final cataloged card of a major baseball personage, were issued on a far smaller scale than a national mainstream set, and are often very difficult to locate, yet are paradoxically often worth far less than the player's "rookie" card (though this has definitely changed in the last few years). With some players, like Ernie Lombardi or Lefty O'Doul, I like to "bookend" their careers with Zeenut cards issued before they hit the show and Zeenut or other cards after their MLB careers were through.