1943 PA Keystone License / Badge

I picked up this old metal badge plate in a box lot while on a pick in upstate PA. I grabbed it because it looks kind of old and it came with a bunch of 1970's era southern fishing license tins, a PA hunting license from the 1930's, and some PA Fishing license buttons. I have no idea what this is and need some help.

It's about 1.5" X 2". It appears to have the Pennsylvania Keystone symbol on it, a embossed 43, which I assume is for 1943 and what looks like an expiration date. It's also stamped with the following characters "A27776". There's a hole in the center that looks like it may be been bolted or screwed to something at one time.

Any help with this would be greatly appreciated.