This appears to be from a set the Standard Catalog lists as 1961 Baseball Player Key Chains (I've always known them as Key Chain Inserts). The set (of at least 69 players, both current and past players) depicts some players with team names, some without, some with cap logos, some without. The 2009 Standard Catalog lists the Gehrig at $12.00 in NM, but in my experience the star players from this set can go for multiples of guide (I'd love to find a NM/MT Killebrew for my collection, and I'd be happy to pay multiples of the $7.50 guide price)...