This has a dual back: the outer back is hinged and lowers down to show another back that can be inscribed. On that back is says "Remontoir 10 rubis." Supposedly "remontoir" is French meaning pendant wound, which makes it a type of watch rather than a maker's name. I haven't gotten the inner back open but from photos I've seen on the internet, it wouldn't matter because the maker didn't identify the movement.
So it's a 10-jewel, probably Swiss made, probably 19th or early 20th century. Pendant wind, pendant set, except that to set it you press the little button on the case (located about 12:45 on my photograph) and turn the crown to set it.
Pretty case. 0.800 silver. I haven't figured out the hallmarks yet.
Acquired: 2019
Circa: late 19th/early 20th century
Current condition: runs fine