60's 70's. Good ratchets overall. Wright makes an open gear like that to this very day. The nice thing is you can hit them with compressed air and a little 3 in 1 to clean and lube them. They're also fairly smoothe. Good boat ratchets too
There are almost identical Companion brand ratchets made by Western Forge and sold by Sears in the 70s. I have a strong suspicion that Thorsen sold their old tooling to WF when Thorsen changed to a newer ratchet design. My Thorsen ratchet of that design is very nice, well machined and smooth. My Companion clone ratchet is poorly machined, rough and has alot of backdrag.
The one I found today is in good shape, but not minty fresh like yours! I do like the action, but I've got to pare down, especially my 1/2" stuff! I presume it would be a pretty sought after model in the classifieds here.