Cast Iron Canning Jar Ring-Wrench: US Made? When?

There aren't very many tools that make use of flexibility in cast-iron, at least in my experience.
Internal-combustion engines used cast piston rings, long ago. I cannot think of another example.
No matter...this wrench does; and to prevent over travel which would break the casting, it has integral stops in the ends of each grip arm.

I would like to know roughly when it was made, and where. There's not a mark on it to answer those questions, let alone who designed it and formulated the specific iron alloy (and perhaps heat-treatment) to achieve such a simple and durable tool.

Like so many old things, it's somewhat of an orphan.

Thanks for looking!

 

Forged

Dimensions?

 

Not forged; please note the ground-off ingates in the first pic, below.

5¾" long, 2⅝" ID, .250" thick at the bead around the ID; ~⅜" diameter of the stop-pads.

 

Now, to make this a lot more interesting: my original assessment of the purpose for this tool included an overlarge and incorrect stroke of foolishness! In measuring the ID of the ring in order to answer terry5732, I tried to fit a modern small-mouth canning ring into it. Lo and behold, to my shame & embarrassment...it won't go!

So...Mea Culpa...as in so many other things, I don't know what I'm talking about. I hereby throw myself onto the tender mercies of my betters, and hope for the best.