yeah IDK the old one that was all seized up is gone now but it looked like shiny pine wood. the new one thats nicer looks more like mahogany that is french polished.
I had to drill it to add standoffs for a dsub connector. when I drilled through it, the outlet of the hole was not super crisp, it reminded me a little bit of how OSB drills on the lip of the hole. Not as stiff as a PCB I guess. PCB kind of have 'chipped' holes, rather then partially attached crumbles on soft stuff. I assume that is a sign of cloth or some kind of puffy fiber, not glass fiber.
I am guessing that wood fiber insulation 1950's stuff (tar bags) mixed with some kind of resin. BTW that is apparantly as bad or worse then fiberglass even though its natural material. On the other hand, as far as my old research went, rock wool, which is a synthetic byproduct (slag) based, is not nearly as bad.
Kind of wonder how rock-wool PCB would do. Safer to drill?