Old Napkin ring

Good Morning
I have bought a mixed lot of napkin rings online. got about 16 for $20. Half of them are sterling mostly from Birmingham. Two had there hallmarks polished to almost unreadable. The one were from Constantine & Floyd Ltd. The one I am doubting is the one in the pictures. It seems to be the mark J.M…J R for John Muir Jr or John Murray. If this is true it will date from before 1858. Can it be?

Is it your picture or is the top a larger diameter compared with the bottom? If so I think that it has been re-made from some other item. I am also dubious about the maker’s mark. If it is JMJR then it was almost certainly not orginally a napkin ring.

Just a bad picture. Top and bottom are same diameter. The mark is the most likely fit. Is a JM another gone letter and a smaler R in the corner. It weighs 20g are 33mm heigh and 45mm at its widest.

Maybe John Millward Banks is the maker. Could bee a B.