Tom C, bender07, and several others who have chimed in with PMs - Thank you so much for your help on figuring many things out. With your help, Here is what I have found so far:
1. The signatures are seemingly authentic (Hooper is the only one on the ball)
2. The ball I believe dates to between 1913-1917 (O in Official more centered above the i, rather than the c), which is really cool since it dates to his playing days, even though it was not signed until 1952:
http://keymancollectibles.com/balls/...seball1917.htm
3. It is personalized to Doug Baldwin, who it turns out was an old baseball writer. There is a reference to a newspaper article apparently involving Hooper from 1937 by him at:
http://takemeouttocapitola.weebly.com/learn-more.html
Baldwin, Doug "Doug-Outs with Doug Baldwin", Santa Cruz Sentinel, Feb. 5 1937
So their relationship dates back at least that far. The post card, which could not have been signed prior to his HOF induction in 1971 i.e. long after the ball in 1952, is personalized "to my old friend Doug Baldwin", which seems consistent with all this.
Really cool, and seemingly much more unique than I had ever thought!
I am not looking to sell right now, but thanks to those of you who have expressed interest. I will keep you in mind if I ever change my mind. For now I am simply thrilled to learn more about this item and to add it into my pre war collection.
Any tips on how to find a copy of the newspaper article? I would be very interested in tracking that down now...
Cheers,
David
Sent from my iPad using Tapatalk