Well, I don't know what else to call it. You should probably have a smith look at it, though.

Hmmm...an odd construction to be sure. Let me see.... As I thought. These two pieces aren't supposed to be attached. Looks like a regular Dwemer shield with this other piece attached. Hope you didn't pay too much for that shield, friend. It's nothing special as far as I can see. The other piece is interesting, though. Dwemer in origin, but unlike anything I've seen before.