Hello, my name is***** am one of the expert appraisers here at justanswer. I would be happy to help you. The following link http://www.psacard.com/Services/AutographedBaseballAuthentication authenticates and certifies baseball signatures. They will also grade the ball and from there you will have proof that it is real and authentic. I have also checked through the teams and players to verify Ty Cobb was there at the 1947 world series. If I may be of further help please let me know.