This phone was found in Australia.

Notice the single hole on the rear of the phone, instead of the two holes on the later GECophones.  Also, plastic grommet on entry point is intact.

You can also the circuit diagram which tells us that this is a  KS7239.

#45

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