I was curious about the time frame regarding the Plomb adjustable wrenches as well so I did come checking. Like Lugz says, AA and the catalog show the first adjustable sourced from Utica. Apparently they were buying wrenches from Danielson before they bought the company which accounts for my wrench dated before the purchase. According to AA they started sourcing from Danielson sometime in 1946. Oddly, AA has an example that Plomb sourced from Diamond with an angled jaw, although I’ve never seen one. Just when I think I’ve got the timeline pretty much figured out, my counterpart in Wales sent me a picture of his that I’ve never seen before. I have no idea who made this one.
Roy, He was the buyer of the eBay Plomb you asked me about.
-Don