That socket looks exactly like the sockets that came with the vintage Screwball ratchet driver I have. There have been several different socket designs included with their set over the years. The sockets that were included when the set was packaged in brown styrofoam look like yours.
The first picture shows a set taken from Google Images that has the original labels still attached, and the last two pictures are of my set. The screwball ratchet was made by S/V tool Co. out of Kansas, USA, but I doubt they were the manufacturer of the sockets. They probably made the ratchet handle and sourced the sockets from someone else. I see screwball ratchets at garage sales quite often, so they must have been quite popular at one time.
