Some electrical fittings in a house I'm working in.
The white tube is porcelain and was the service entrance through the outside stonebuilt wall.
The tube cut off just above the mantelpiece is an original victorian acetylene gas light pipe. It's the equivalent of a 5 amp round pin socket, plumbing in lights around the room goes back long before electricity.
I still have a few of those GEC light switches in my box (pic #2 top/middle and pic #3), although they're a little cleaner!
I'd put the MK sockets at early/mid 1950s, which is consistent with the rubber-insulated cables. The BS1363 standard didn't appear until the very end of the 1940s, so there weren't many British homes which had these sockets before about 1950 at the earliest.
Crikey, Talk about moisture damage!. Them switches used to be used here in NZ quite prevalently. 5A switching load aren't they?, I have seen some as low as 2A, from back when lighting circuits were rated at 5A a piece. I see on the switch bodies that they had an English patent, that seems strange when at least one company here made them, but the majority were imported from Good Old Blighty!.