BT Ambassador 8100R telephone, probably made by Pye TMC, Airdrie, Scotland, 1981.
This was one of the first telephones produced as part of the BT Ambassador range of the 1980s. It was also the last rotary dial designed telephone (as opposed to push button dialling) in the range. The Ambassador range was the first UK telephone designed for the plug-and-socket connections that were replacing the hard-wired connections of previous phones. It was designed for the British Post Office.