Hi,
The council house built in 1953 that I was born & brought up in (1954) had the unswitched version of the MK socket shown in post 33. There were just four in the whole house
I've still got a couple from when it was rewired in the eighties. The earth connection was unusual in that it was a metal strip about half an inch long with two screws that trapped the earth wire. L&N terminals were conventional.
I think the council provided some MK plugs too.
Cheer de Pete
PS, Love this thread