There are four black angle metal foil corner pieces that just fall out of the case. They are about 4 mm long and 2mm on each leg. Have no clue what they do or where they go.

Ok, a word of caution that can't be overstated. The off screen switch, the lock swith, and the volume switch can all be broken easily. I would stay away from this area completely. The bracket on the off switch is tack welded and can be broken. The volume/lock swith can be malformed to become unusable. So avoid the area and you will be better off.