According to the Standard Catalog these charms were released around 1950 and are listed as "1950 Charms" in said catalog. They came packaged in little plastic bubbles and were found in vending machines, which is totally awesome. The border around Campanella is more orange in-person and it's quite a small charm.
Per Bob Lemke in the 2011 Edition of the SC:
The date of issue for this novelty item is conjectural, based on known player selection. Packaged in plastic bubbles for sale in vending machines, these charms are found in several different shapes - rectangle, octagon, etc. - and colors of plastic. A black-and-white photo appears at center with a loop at top for hanging. Size also varies but is about 3/4" x 1-1/4". Players are not identified on the charm and there is no number.