There's a permanent ring guard in it. I meant to tell him to remove the ring guard, but I forgot to do so. Now that I see my notes, he called it a "ring shank." I imagine that once I have him remove the shank, I'll be in a better position to tell you more info.
I don't think he said what era it was from, although I think I remember him saying that it was old, whatever that means. Anyway, here's a side view picture of the ring. You can see the ring shank in this picture.