I agree. It does. Stanley bought Atha for their hammers and re-used that name as a brand for their top of the line ball-pein hammers for years. But it's very possible that they used Vlchek for their "Standard" line. Frankly, I never thought about it before.
The 1940 Stanley catalog on IA/ITCL, linked
here, shows the "Standard" with a regular handle, but the text indicates that it came with an octagon-shaped handle. It's possible they were getting their handles from the same source as Plomb. I have never brought home a Stanley Standard hammer and I see them regularly, but I can't recall seeing them with octagonal handles.
It gets a little weirder. If you look at the 1941 Stanley catalog that Don excerpted in the G503 post he linked, the "Standard" line does NOT have octagonal handles, but a third unnamed line does.