I picked this up a couple weeks ago and wondered if anyone had any information on it.  Marked with number 729 and 7/16" & 1/2" [bolt sizes?]
Made by M.M. Williams Co.
Was it made for White Motors?  I doubt it was made for White Sewing Machines.  Approximately when was it made? 
I looked on AA, but I admit I didn't look through every article.  Also, I couldn't find anything on MM Williams, only JH Williams when I Googled it.

It is the truck company, the script is distinctive with a loop flourish conecting the capitol W with the h. It is also J.H.Williams, the W in a diampnd forge mark is williams. Perhaps a misstamping on the name. That wrench in that size is on Alloy Artifacts BTW.

> [bolt sizes?]

Yes,  #729 standard size wrench for 7/16&1/2 bolts

To date it, need to know what it says under williams, if anything...

The very small W in the diamond mostly appears before 1914 ish, but not conclusive...

Stray weird trivia, in the 30's, White was run by a fellow named Black....

Thanks for the info, Rusty.  I checked JH Williams on AA and sure enough, there was the wrench.  Why I didn't check it before, I don't know, must have had a senior brain fart.
We're at a friends on the lake for a couple days, so I'll try and read the stamping again, with a more powerful magnifying glass, when I get home.  I could have sworn it said "M.M. Williams.