Photos are a little hard to see the diamonds, but they look like rose cuts to me. Do you have clearer photos of the diamonds to see the faceting? The photos are a bit hard to see.
What markings do you see?
Looks like it has a yellow gold body, with a platinum top probably, which is not uncommon in that period.
You have some fairly good prong damage on the left side. I would not wear it without getting it checked and prong work done first. Is the accent stone at 9 p.m. missing?
The ring has very nice bones, but I would give it some tlc with a bench before wearing it.