Napkin rings - strange number mark

These napkin rings appear to be Victorian. They appear to me to be silver and not plated, though I haven't measured specific gravity so I can't say for sure. And they have a mark, but "575" isn't a mark I've seen before. I would guess they might be Chinese or Japanese due to the engraved bamboo stalks and leaves. The engraving is hand-done (similar but differs significantly between thetwo), but the fleur-de-lis seems to be stamped. Strangely no seam that I can find.
Has anyone seen that mark before - or is it just a production number?

 

They look aesthetic movement, for sure not Chinese or Japanese.

 

Agree - Neither Chinese nor Japanese. Probably US silver plate of the Aesthetic period, with an item or inventory number. Too bad they didn't mark with maker.

 

Polish it, maybe you will find a mark.

 

Is it made from multiple pieces soldered together? The the Fleur-de-lis pattern appears to have made on a rolling mill. Seamless tubing has been around for many years,there are a couple of ways to make a solder seam disappear.