See photographs.
A Shaisho black and Matsui cream wall phones.
These are CORDED types from the earlier days when you were first allowed to own and plug in your own phones. (Previously it was compulsory to rent your phone from the GPO, forerunner of BT).
These plug into the master socket or extensions.
Wall Phones - Retro (Bilton CV22)
This offer has been gifted to someone and is no longer available.