Query about 5amp round pin plugs

[ToughMudder]

Firstly, I nothing about electrics so sorry if this is a thick question.

Moved into a new house which has loads of 5amp round pin plug sockets for operating lamps from the main light switch. The lights are all on a Lutron system.

If I want to plug two lights into a 5amp socket (for two bedside lamps) can I just swap the plug on a normal two-plug extension cable for a 5amp plug and use it in the 5amp socket?

[ToughMudder]

Simpo Two said:

A cable that can carry 13A can also carry 5A.

Wonder if 5A round pin adaptors are still available?

So does that mean my idea would work?

Can't find 5A adapters anywhere. I can find 13A to 5A but I'm looking for 5A to 13A (for two plugs).

[ToughMudder]

That would be ideal but I don't think they make them any more. Not sure I want to buy one off ebay that is 40 yrs old.

Would it be possible to use an Indian adapter (I think they use same size as BS546, Type D) like this : https://www.amazon.co.uk/AMOS-Universal-Universell...

If so could I then add a two way normal plug extension to that?