Gus Grissom Autograph

(Wally Crabtree)

I acquired this one dollar silver certificate in change from a store in Florida. At the time, I did not look at it closely. Late that night, I saw the signature of Gus Grissom. I have checked the signature and it appears to be original. Attached is a copy of the dollar and the letter that I had received back on it. Please let me know what you think and the possible value of the signature.