What is the wear on the ring like? You would expect thinning of the band at the base and smoothing wear on the edges of the stone mounts, edge of ring. It looks like two diamonds are missing (those holes either side of the red stone). You might want to get that stone tested as paste ie glass was very common in Georgian / Victorian rings. It could possibly be an Indian reproduction in the Georgian style. They are particularly fond of doing that “antique patina” to silver ! And I don’t like the quality of the workmanship. It’s very “irregular” perhaps to simulate “age”. If you look at genuine Georgian rings, youlll see there is a difference between very old thinning, worn, age damaged prong work and the uneven and unequal prong work around the red stone. f the price is right and you love it, great, but I wouldn’t pay the premium for Georgian / Victorian jewellery because I’m not 100% convinced.
The prongs on the ruby give me pause. I’ve seen not perfect looking prongs, which makes sense because the piece was hand-made, but the prongs are usually shaped and refined in a piece nice enough to have a ruby and diamonds in 18k. The prongs around the ruby looked smushed down to me. Of course, it could be original and the ruby is a replacement stone and that’s why the prongs look that way.
It doesn't look right to me to be Georgian and it's not Victorian, bit of a strange hybrid. Your photos are stretched looking too for some reason which isn't helping. It looks to me that the inset metal has been heated(?) in some way to blacken it and it's discoloured the outer metal. I have a thick gold bracelet with links taken out. The bracelet was cleaned after but the removed links weren't and they look like that, slightly iridescent colours. Also the bit around the red stone is in nice condition but it looks quite thin to me, I would expect that to be more bashed about. Have you photos of the back?