GPO 250

The model 250 is a portable telephone for linesmen or field engineers. It can be used on local battery (LB) and central battery (CB) lines. It houses a battery, a ringing generator, a buzzer, and a dial. It was introduced in the late 1930's and it was also available in a military version. The case has a leather look, but it is a hard red/brown plastic moulding.

I have a number of 250 telephones. I modified one of them to be used as a GSM telephone. See: https://youtu.be/fEoDGGnNtCI