Hello Charlie,
The pin you have was commonly sold at baseball Stadiums in the 1950s. It could have come with an attached ribbon, and Bat, ball, Charms. They usually sell for about $25.00 --$30.00. With the Ribbon and charms you can get more, without they can sell for half.
The same pin you have is currently on eBay with 3 bids at $7.50 / 5 days left. I'll keep an eye on it, and post the results.
UPDATE: 9/28 The Brooklyn Dodger pin sold for $34.33 on eBay
I have a similar pin for the Yankees with the same style that came from the same era. Recently a Giants pin like the one I have sold on eBay for $10.00 below are samples of the pin like yours with the ribbon, and charms, and the pin that is similar.
Steven KeyMan
