Since Munson was mentioned, I want to point out the oodles and oodles of unused postal cards that Coach's Corner has sold and please click on this Jackie Robinson:
http://www.myccsa.com/Lot.aspx?LotID=196227
Now check out these that they have sold in the past (outside of the Cash, which was a ball), but you can see where were going with this.
And then a few Satchel Paige's they have sold, and of course this month they are offering another unused postal card and this, which matches the scans provided.
http://www.myccsa.com/Lot.aspx?LotID=198043