Jim, I don't remember having any trouble drilling out the rivets on the handles, or any of the holes, so I'm pretty sure it's just chrome plated steel. I used the holes from the handles to screw on the neck block and tail block. The frame in these pics screws onto the blocks on each end, and the cover of the pan (bottom of the guitar) screws through its handle holes to the two legs attached to the frame.
I'm sure the sound suffers especially from the fiberglass spider bridge that is too flexible and loses and modifies a lot of string energy transmitting it to the cone.
I'll try to find a clip I made of the different guitars, upload it to soundcloud and post a link.