[brookdodger55]

Great looking poster love the Wills and the Drysdale.
Just a though, I think what you have hear are posters of player's that were under contract / spokesperson for the company.
(See bottom right stating advisory board same as spokesperon .These were probably given out to all sporting goods stores that sells spending gloves/other baseball related items. I would try contacting Spaulding directly. This is part of there marketing advertising programs from the 60's. I'm sure they have some old timers still on staff that might be able to help. I would also try to search for a historian that focuses on Spalding Sporting Equipment, not easy but it's out there.
Mike