Donald Qualls
Subscriber
My understanding from having taken the front off of a few of them is that it's a sandwich of very dense and rather thick metal making up the front and back covers and a bakelite chassis with some metal for the shutter mechanism to ride on.
Okay. I've only had a couple parts off one, back in the 1970s. OTOH, Bakelite is/was often filled/reinforced with fumed silica or glass fibers, making it nearly as dense as solid aluminum.