Please help to identify the mark, period, original country of this necklace.
1/Looks like a "II" in the Omega image.

2/Marked "JW".

3/It's really hard to read, coz it's not clear naturally. However, it seems it's a "V" on the left corner and a "2" on the right corner.

4/Marked "800" on the pendant. It's an unclear mark on the left, which is the same as the mark in the 1st picture.

5/ Full image of the necklace.

In addition, the "835" mark is on the necklace chain which isn't displayed in the pictures. Also, nothing is on the back of the pendant.
Thanks a lot for your help in advance.