Even though the number of components is just about the sane the schematics look a lot more complex than those of our W48 phones from the same era.
5 wires to the dial... ours had four, later ones only three. Our rotary dials basically consist of 2 switches. One is open at idle and closes when the dial is turned. The other one is closed in idle an opens while the dial spins back, generating the dial pulses. The correcr technical term for rotary dial was and still is "number switch". The more familiar term is "dial disc".
A few weeks ago I took apart two W48 phones and did loads of measuring to find a fault. I eventually tracked it down to all dial wires being swapped over.
The only common problems with those phones are faulty microphones and handset cords with broken strands. Everything else is inestructible. The cap is only 1 microfarad here IIRC.
The oldest W48 models (mine is from 1949) had a braided cloth handset cord and plastic line cord (three wire for single line phones, th third wire was earth where required, party line phones had a 10 wire cord). Later 50ies models had a round cloth cord for both hand set and line (maybe mine had a cloth line cord originally too, the dial was definitely replaced at some point in the 1970ies or later) and from about 1959 on they had black plastic cords.
Our W48 is in regular use, every visitor jumps upon hearing it ring... I have to admit though, sometimes it even makes _me_ jump when ringing close to me unexpectedly.
Think I already told the story of the Zylmurbafi dials...
