help with antique gold and ruby fox head cuff links

[morisaur]

I recently bought these cuff links on ebay. They were advertised as being antique, either of British or Irish origins, with ruby eyes.

I'm trying to figure out if they're original, if they're actually a match, where they're from, and how old they are.

The main thing I'm wondering about is that the two cuff links are slightly different. First, they're a slightly different tint of gold (you can see the one on the right is a slightly more yellowy gold). The bars on the back are also slightly different (one joins smoothly while the other one overlaps). And then most notable of all--one of them has hallmarks on the forehead between the ears while the other one has them on the oval back of the cufflink. The marks appear to be the same but I can't figure out why they would have been placed differently.

As for the marks, what I've been able to figure out is that the first one is "O.C" (maybe the maker's mark?). Second one I can't figure out. Third one appears to be the date letter and looks like an "O" although I can't tell if it's a big or little one. Also I could be wrong because it looks like the top of the circle isn't closed. The last two marks are a 9 and 375 which are the purity marks.

Anyone have any idea who O.C might be or what the second mark says? Also any idea about the year mark?

Thanks!

 

[morisaur]

Anyone have any ideas?

I was able to look at the marks with a loupe yesterday and it almost definitely looks like it's Dublin and the year letter is a C in a square with notched corners, which would either be 1799 or 1970.

I can't figure out how to determine which it would be. And if it is 1970 and not antique as I was told is $330 still a reasonable price for these?

Thanks for any insight!