I know these aren't cards, but I'll post them anyhow since I know many of you are Clemente and Aaron fans.
I just bought about 20 items from a guy who has a pretty amazing collection of old newspaper clippings and inserts.
This was cut out from a 1955 Sporting News publication.
This was an insert in a 1955 newspaper.
And these are advertisements for cards readers could send away for back in 1912 and 1913. I believe the player shown is Shoeless Joe. Zoom in on the first one to see quite a list of names.