Unusual markings on silver tone vintage jewellery

Unusual markings on vintage set - any ideas please? :sparkles:

Bought this pretty lil’ late century vintage set and I think it’s peridot and rose tourmaline, but trying to decipher the metal.

Weird hallmark that I’ve not seen before. Has a makers mark that kinda looks like ‘MISSA’ or NESA for a makers mark… and on the reverse there is a mark that looks like it says 10%.

I can’t help but doubt that it’s white 10ct gold because I don’t think the pearls are real and the links on the bale aren’t soldered. If anyone can share any wisdom as to what they might mean, I’d really appreciate it!:sparkles::pray: Thanks!

Hello, it doesn’t look silver. Have you tried to bring a magnet closer?

Thanks for your reply!
I have a very strong special magnet here and it is very very slightly attracted, but hardly, when compared to other metals around the house.
It’s not attracted to a normal fridge magnet.
I had assumed it was silver as it would be unusual for an alloy mix to be marked with a number (but not unusual for it to have a makers mark).
Hmm! Curious!

If it was slightly attracted, it is definitely not silver. It must be an alloy with nickel and still has a little iron or even high quality steel.