Thank you everyone for the replies!
Big Daddy- Appreciate you pointing out the Seaver. I think I had him incorrectly labeled, and have adjusted the original list.
OC- I will let him know. He retired back in 2004, and is in the process of downsizing. Definitely a great memory for him.
Acquarian- Thanks for the advice! So it seems it would be finically prudent to get the ball authenticated if he were to sell it. Would that be expensive? I have a small collection of vintage cards, but I am by no means an autograph expert, and it's not like he's traveling around to trade shows.
He may be slightly off on the date. He does have a signed George Bush baseball as well, which may be from the same event. I've included a photograph of that ball below.
