Red phone from the books

DutchJamesBondFan

Hi all,

I was wondering, the red phone from the books, what kind of phone would it be? For me, I always pictured a phone without dials. Just a phone that M can call, but 00's can't call M. Something like a

Cortelco from (please correct me if I'm wrong) the 50s I believe. Maybe I am wrong and somewhere in a chapter Bond does call to M. Thanks in advance for helping me research. Cheers.