In article ,
Andy Wade writes:

Green protective sleeving: pre-1966.

I suspect that's a mistake. It should probably read:

Green protective sleeving: 1966-1971(?)

Green/Yellow protective sleeving: 1971(?) onwards

Non-13A socket-outlets pre-1955.

Should also add:

13A socket-outlets: post-1945 (Introduction in 1946)

Very interesting though.

--
Andrew Gabriel