Thanks guys, for the replies.
The Crescent Brand adjustables seem to have seen only minor changes to it's basic design since the patent was filed. Up through the 40's, the panel on the handle where the Brand and size is stamped is closed off before it gets to the adjusting nut. That panel was later opened to the adjusting nut, sometime in the 50's I believe. So, I think this wrench is pretty old. Obviously with no patent info on the wrench itself, it's difficult to date.
The patent drawing shows a hex broaching for the hanging hole (31), but I've never seen a Crescent with that feature.
The language from the patent is:
"A hole 31 is provided in the opposite end of the wrench handle 10 from the head 11 for hanging the wrench and in order that said wrench may be ready for instantaneous use without the adjusting of' the jaws :for the size nut most common in use, for example, a one inch nut, said hole 31 is made hexagonal and of the size most desired."
I wonder if they never landed on a size that was "most desired".
Patent image: