[drc]

I suspect a lot of the exemplars are from contracts and legal documents. I've seen Ruth signed contracts, his driver's license and even a Ruth signature that was notarized. I've seen Rube Marquard's visa and Joe Jackson's signed Last Will and Testament. When these types of items are known to have coe from player's estate or team, then there is some reliability involved.

Also, some official signed documents may be viewable through the military, government or schools. Even if you can't keep the Christy Mathewson signed Army pension document you view at the Army's archive, you might be able to get a photocopy. Perhaps you can visit Columbia University and see if you can obtain a photocopy of a Lou Gehrig's signed college document from when he was a student.

Greta Garbo's is one of the rarest and most desirable Hollywood moviestar signatures. As her estate was officially auctioned off by Christies' and it contained her signed driver's license, it can be said there is a reliable Garbo signature for authentication reference.