So, you take this flat piece of silver with a design sawed into it.
Then you bend it into a not all that circular shape, making sure the ends are flush.
Then you apply fire and solder to make it into a continuous circle-ish shape. You are not overly concerned about how un-circular it is at this point. It is supposed to look like this. Really.
Since the fire has made all black, you pickle it to remove all of the oxidation from the heat. Then you put it on a ring mandrel and hammer it until it is round. This is very good stress relief unless you hit your finger.
Then there is filing. A lot of filing. And sanding. A lot of sanding. I am nowhere near through sanding.
Still. Even though it isn’t quite shiny yet, I have a circular ring with appropriately soldered joins.
It even fits.