Thanks for posting the back Bycin -- I didn't realize that you had added it via Edit. It's interesting for sure -- and the last image of the earring in your hand provides a better idea of scale, since they had read as larger in size (for me) in the initial images, but now appear to be more 'doorknocker' in size and style.
The earring appears to have a bit of goldwash -- looks like rose gold (is that right?). In some pics, it looks more bronzy, and hard to tell. If they are very bronzy and lightweight, they're likely to be later --if not, I would say you're right, as they look more 60's/70's ethnic and the prongs look very 'costumy' in style (faux prongs become more popular later on). I'm sure you'll get more feedback shortly.