The Duro adjustable shown on AA is described as having a "square shouldered keyway",
https://home.comcast.net/~alloy-artifacts/duro-indestro-p5.htmlwhich is further described as a patented construction feature of Williams adjustables. Mr AA deduces that the presence of this feature identifies the wrench as Williams made.
I see this same feature on many brands of adjustable, some of which I would not expect to have been Williams made (disclaimer: not an expert). The ones I have are marked Crestoloy, Herbrand, Barcalo, New Britain, Channelock, Diamond, McKaig-Hatch, Proto and even Craftsman. I suppose anyone could use the square shouldered keyway if the patent expired.
Here is the Duro I have. It does have the square shoulder keyway and a Williams look, but not a vee opening like the AA example.
I'm just kicking the can (of worms) here, but does the Powr-Kraft have a square shouldered keyway? It doesn't seem it would help in identifying the maker at all; just curious. That is certainly an unusual and interesting wrench.