[bakophone]

I've just bought this wooden telephone, mainly because of it's candlestick receiver. I think it is British probably from the 1920s but I am struggling to identify it further than this.

It is contained in a GPO No1 bell style wooden case and has a button on the side. The mouthpiece reference number starts with a C (GEC?) but there are no numbers on the back.

I did wonder if it was a railway telephone, but does anyone know what it is?

Thanks