www.925-1000.com

Thanks Trev, that's probably correct (unfortunately I still hit a dead end). Appreciate the input.

This necklace has 925 in an oval, but the maker's mark on an end loop doesn't follow norms. It's too small to get a better photo, seems to be MI'Or (I assume MI is Milan). It's not in a cartouche, and there are no other marks. It's a thrift store find. Any ideas? https://i.imgur.com/5h0fzZq.jpg