Those are great! Definitely original. I agree that they look medieval, which is fun. And yes I think arts & crafts when I see the hammered look. I could be wrong here but I know another similar house w/ original lighting and they have round bulbs. It's a pretty cool look IMO. They're also frosted, sort of a pink color I think, though I could be wrong about that.
I also think I've seen ones a little similar (reproductions) at rejuvenation house parts (.com)
It would be helpful if you would send a photo of them. I have seen some mighty ugly old, origanal ceiling fixtures. If you wish to be a stickler for detail, clean them up, get some interesting globes (they make cool Edison Copys) and get a dimmer.
If you just can't stand it, find what you like and replace them.