In my latest Forbes post, I do a bit of detective work on a vintage "signed" Mantle letter, with the help of Marty and Ron Keurajian

http://onforb.es/1SMtZbD

If anyone has seen letters like this, please let me know. At a paper show held 30 years ago next door to the former site of the Brooklyn Dodger's office, I came across hundreds of pieces of Dodgers letterhead which I regret not buying up. They don't make it like this anymore... 

David