I am going to open myself to trouble with this one. I found this wrench in my tools in a wooden box, and don't remember who gave it to me! If it is someone here, I apologize for my senior moment.
The only marking is what you see- L JARY . Nicely done, like it was factory, or a good craftsman. I did use some chalk to highlight the letters.
The wrench is 7/16" by 1/2", and is 5 1/2" long and 1/4" thick. Built like an engineer's wrench or a post wrench.