The "old" british standard is even cooler: https://www.plugsocketmuseum.nl/OldBritish1.html
You can still get similar to those today. 5A sockets, for plug in lighting.
Yeah, those are the same standard - they're still legal. The large ones were used in theatre lighting until recently (wiring is radial and you don't want a fuse to blow 5m above the stage in any case).
I think India still uses them, too.