What is it? I've no idea.
Neither does the staff at Lawton OK Museum of the Great Plains.
It appears to be homemade, not commercially manufactured. The sheet metal appears to be all copper. The soldering looks more like silver than lead based solder.
Past couple weeks bet I've wasted 10-12 hours searching internet, haven't seen anything like it.
You can see where smaller "tab" broke off. Long thing (handle?) isn't a tube, it's a flat piece formed into a "U" with a little notch in the flattened end.

Edit: Location in enclosed display at Museum of Great Plains, Lawton OK. Staff knows no more about it than I do. (Aside. GREAT place to bring the kids. Spent entire afternoon with the Gkids (6-8-10-13yo) few weeks ago and they enjoyed the hail out of it. Almost everything is hands on.)
I guess size about 12-15" diameter, overall height 15-18".
All joints are soldered, making the whole thing one single fabricated piece.
No markings of any kind on it.
I've got nearly 100 email guesses, including replies from 3 museum curators. No one yet can tell me positively what it is or what it was used for.
I kinda half wonder if it's something like a trade school fabrication project not to make something useful but to teach a process. And rethinking, no, no way, whatever it is it's some kind of formerly-useful, and used, 'tool'.

Still of some sort. Could of been a hillbilly still for making essential oils.

still of some sort?

Kind of scary (for you) we used the same language. Great minds think alike! Of course we do as well.

It looks like a burner of some kind. Let's see how strong my google-fu really is.

Still

Still

Just a couple stupid questions asking for education.

If it's a still, then why is there a pressurizing pump at the top of it? And why isn't the outflow at the bottom of the tank versus the top? I've seen stills, I've seen my grandparents' still. But I haven't seen one quite like that before.

sous-vide

Sour mash distillery

Another old still

Doesn't look like any still I've ever seen.

Looks to me like a homemade water distributor, maybe for a small garden or a greenhouse.

Make a bracelet out of it and never get sick again.

I am guessing its a water heater so you can pump pressurized water into several hotel rooms.