Expensive ask me how I know...[/url]
Yoke patent 2,479,661, granted 1949. Yours looks that old. I've only ever seen General and Craftsman.Not marked.![]()
Maybe. With other vintage approaches, including Lutz, SKROOZ-ON, SHUR-GRIP, or even Disston's coiled spring ferrule, it wasn't one size fits all. You had to have a few different file handles for different size files. I'm not sure how much time it saves, if any, since in my experience it's just as easy to reach for a separate file-in-handle combination as it is to remove a file and reach for another file to put into the same handle. But it does save some space.Seems over engineered to me.![]()
I've only ever seen General and Craftsman.

Those look clever, well made, strong and I have never seen them before. Probably yet another desirable tool only available the other side of the ocean..!
Well done Tostal!
I just found it, still available, on the website
https://shop.snapon.com/product/Pla...Adjustable-Jaw-File-Handle-(Blue-Point)/GA98A
£15.78 but the item is back ordered so I will put it on my Christmas wish list..