Adding my group shot reveals
11/16 - 7/8 BS
5/8 - 11/16 BS
3/8 - 7/16 BS
5/16 - 3/8 BS
I have no recollection of where, when, who, why, what these were obtained.
I regularly pass on ground out jaws, owners markings etc but can say I’ve never seen a busted jaw.
It would be an interesting...