> the way it was stamped
It is cold swadged, thus the odd appearance inside. It could mean it is old(<1930's) or cheap (later, to the 60's I'd say) How swaging/forging makes a better socket, but is harder to do.
It could just be something like a bed-wrench, EG a cheap wrench that came with something to assemble it...
On the other hand, it resembles APCO's patent drawings a bit...