I can't say anything about the tool, other than if it were modified I'd like to know what my dad used it for. There is noticable discoloring from heat on the wrench area. The problem is the number on the wrench is not showing up in my searches.
I have an old tool of my late father who was a master mechanic. He worked at an Oldsmobile dealer but knew many cars and specialized in transmissions among many things. The tool is a Cornwell with markings 2304. Has a round handle to a flat and curved end with a 12 point 1/2" box end wrench...