[riverdawg]

"... pre-plastic material"

Probably Bakelite, which was commonly used for telephone housings before 1950 or so. I think it is considered an early type of plastic, although it is harder than modern plastics. I have a restored Art-Deco style Bakelite phone from the 1930's with no rotary dial; so the phone will ring and receive incoming calls but you can't use it to dial out. (I'm thinking about putting it in our daughter's room!)

[old-ager]

> Bakelite

Right; I could not recall the word. Brittle, flaky brown or black stuff. Phenolic was another word that came to mind.

[old-ager]

> can't use it to dial out

You actually can, if you click out the digits on the earpiece hanger. It's not very hard. 1 is one click (brief hang-up). 2=2, and so on. The system is pretty tolerant of inexact timing. Try it!