I doubt either one was correct.
We concur!
It has pocket size going for it, matching either of those applications, but not much else.
A number of bicycle wrenches - spanner types (e.g., Tribune, Black, New Rapid, etc) - had 3-way configurations, and sometimes even more, but not all square openings. We've never seen any 3-way wrench Singer or Simanco wrenches, in the wild, or in a period Singer or Simanco catalog. But our main reason for doubting those possibilities is the construction. Most Simanco wrenches are pressed steel, and the ones that are forged - I have a few - are fairly thin. Ditto bike spanners. This thing looks and feels like the Mighty Joe Young of King Kong 3-Ways. Small, but massive at the same time, if that makes sense.
But we're not any closer to identifying it than we were last July.
It still kinda sorta seems
tank-ish to us. If not oxy, something else. We have Airco wrenches with square openings, also those little Prest-o-Lite jobbies.
It also kinda sorta looks to us like it got promoted from farm implement wrench, if you're following the allusion. There are A LOT of farm implement wrenches just like this, with arcane numbers, too, but they're cast, from malleable iron, not steel, and they're not stubby.
Finally, a word on those aesthetically appealing geometric raised shapes. That smacks of machinery wrench to us and those openings were square. But again, not stubby.
