I have boxes and boxes of NOS rings in different sizes and if you get stuck, I see some 2 1/16 X 1/8 in the pile. I make fixtures to hold rings and that way they can be turned to the proper thickness.
Mumbles, that must be quite the feat to hold a ring in a fixture while you
machine it down. If you have any photos of said fixture, I’d get a kick
out of it.
I watched a young English fellow, Mr. Crispin made some rings for his
model engines on YouTube, starting with cast iron pipe. Looked like
a challenge!
Prepare to be boarded!