I've gone all 70s and bought an Ericofon! And it works!
It was in the window of a flea market-style second hand store in Glebe today, with a price tag of $60 - and a little Internet research has just shown me that the current asking price for a reconditioned phone is $AU 289.00!!
"The Ericofon is a Swedish telephone handset created by Ericsson. It was designed in the late 1940s by a design team including Gösta Thames, Ralph Lysell and Hugo Blomberg. A specific feature of the telephone is that the two major components--the handset and the dial--are combined in a single unit. This one-piece design anticipated the evolution of the typical cordless phone and cell phone by several decades. The Ericofon is considered a landmark in plastic industrial design. The serial production began in 1954. The earlier models were only sold to institutions, but in 1956 production for the open market begun in Europe and Australia. In Sweden it is known as the cobra telephone, due to its similarity with the serpent."
When my family moved house in September 1977, we excitedly put in a request for a "Harvest Gold"-coloured Ericofon, like the "Ivory"-coloured ones we'd seen the "Homicide" TV detectives use, but we were notified by the then-PMG that, even though the model was still depicted in the brochures, the Ericofon had just been discontinued. We had to make do with a more standard 70s two-piece rotary dial telephone in Harvest Gold, and my paternal grandmother took custody of the more classic, angular black model the family had used had since the early 60s.
Since I now have a very 70s writing desk with Aussie showbiz connections, I figured it really needed an Ivory-coloured Ericofon somewhere on its surface.