I believe that to be a mid-1940s Plomb-manufactured ratchet. There was actually a thread within the past few days showing its similarities to the "Wright Field" Plombs manufactured during WWII.
I wouldn't trade it in, but my interests might be different than yours. Personally, I'd give that thing a good cleaning & use it or keep it as an oddity! You will see examples on eBay periodically (they are relatively rare) and they typically fetch ~$20.
EDIT: Right! It was v8garage's thread!