A blast from the past here, I had one decades ago in an old Datsun Cherry estate.
I have just been given this, it is a Pye Cambridge with production life 1961 - 1970.

Originally AM with an output of 5-7W this one has been converted to amateur radio use on FM.
It is not small, there is a boot mount chassis with remote control head and speaker and microphone. Very Z cars era.

These were used as early radio telephones with a maximum of six channel, call signs and one way speech (..over).
This is the boot mount chassis:



The control box and speaker, you can tell it's a radiotelephone 'cause it says so:



The microphone really looks ancient, plus being as large as a modern smartphone:



The transmitter section uses valves (ooooohh):



It still works on transmit but not on receive. In reality it is a museum piece, here is an original photo from Pye: