Here is an experience I had with a Casey Stengel signed, game used autographed baseball which was authenticated by James Spence and sold by James Spence to the person who sold it to me. It came with a lifetime guarantee FROM JAMES SPENCE. It was subsequently sent to JSA who rejected it.
My story is here.

http://stangelbros.com/2014/09/17/ri...ime-guarantee/

Eric