I don't know about Jos. Shaw but I have a couple of SHAW doe. I remember seeing a few posts on Shaw, did you try a search?
Yeah, goggle didn't have anything ebay didn't have. Tried Joseph Shaw wrench, tool, company, Toledo.
There are/were 2 or 3 DBE wrenches up for bid - the exact same as mine, 5/8 x 3/4.
Oh well, it's a nice made wrench in sizes I need, so, onto the work board it goes.