I got a bunch of these from the mines; they popped up enough that I sold 'em, figure I can go back and get more if I need them. I've been trying to work on my smithing, but either I'm doing something wrong or it takes a VERY long time to even get to lvl 1 of a craft. So, all these toys that require higher-levels, eiter I save them if they're rare or sell them if I can get more easily enough.
I think the proper name for this item is a Quadav Backplate. And I've seen people using a tradeskill process on numbers of this item to extract the Darkmetal in them. Considering that Darkmetal is a Rise of Zilart-added material, I imagine the skill required for this is hideously high.
This is not the only monster-drop 'useless' armor piece that I've seen refined either.