wrote

I'm pretty sure Britain used exchange names as the US did. When did
Britain go to all number calling?

Outside London (and other large cities) exchange names lasted into the
1980s. However, the letters of the exchange name were not directly used in
dialling. Long distance calls used the national dialling code for the
exchange, but local calls to a nearby exchange could use a local code
instead, and calls to the same exchange still do not need the exchange code,
only the number.

Peter