Hi Richard
Its a remote unit for the 153 set - late WW2
I've never seen a 153 set . The 153 set was made in small numbers by AWA , it was a larger transmitter . The receiver for it , the 8c , I did have one years ago
All made by AWA .
http://www.qsl.net/vk2dym/radio/No.8a.htm
BTW I think the sets are late WW2, not 1950 but not sure. I did have a manual for the 153 set .
quote "Not shown is a curious cylinder housing the operating controls and mounted with the plugs and sockets for the interconnections between the various items."