Phone is the same as the prototype featured in an article titled “A New C.B. Microtelephone” in the 3 October 1929 edition of the Institute of Post Office Electrical Engineers Journal (I.P.O.E.E.J.) – see gallery.

The article clearly shows a metal phone with the early handset with 4 screws attaching the mouthpiece, and simply a “b” in the handset oval – exactly the same as this phone. The only difference is that the phone in the article has a dial blank and this has a 1929 Siemens small centre dial.

The cast metal base has no inscriptions or circuit diagram pasted on top.  The other 1929 bases that I have seen are marked GPO S-1929 and have either a Siemens 82 circuit diagram or a GPO 162 circuit diagram.

When this phone went into production, the body was made in Bakelite. Only the prototypes featured metal bodies.

#F10