This is the one I have on my roadster. The oldtimer I got it from called it a "Draw Bar" and claimed it was an original (It sure has enough pits to be).
It looks like it may have received a flat tongue or some such which was held in place with a clevis pin. I think the modern ball was a later addition.
It looks simple to reproduce using one of the currently available spare tire guards, a length of bar stock, and a piece of channel or angle iron.
I dunno but it pulls my little utility trailer just fine.