In the early 80's, we made a lot of parts from Phenolic material, which can be had in many different formulations, depending on what you want to do with it. It is non-metalic but machinable.
this is a good explanation site.
I specifically remember using a lot of the light green and tan material, and we made rocket guidance housings and gimble blocks out of it.
"If you don't know where you're going, then any direction will do." -- Lewis Carroll