Here is another pin which I believe is from the late 1950’s or early 1960’s. It is a little bigger than many of the small pins found pre-1950 and this one doesn’t have a ribbon. But I have never seen another one of this pin (with or without a ribbon).
This pin looks similar to one of the earlier pins I posted (with the two plastic footballs players tackling each other). Both have the same picture of the football players on the top half of the pin. The difference is below the picture this pin just says Oregon State while the earlier pin says Oregon State Beavers. The players in the picture do not have facemasks, which would likely put this as a 1950’s era pinback. I haven’t seen this pin with a ribbon or charm yet.