They had never been in place because the earth screw was fully home
and had never been in contact with the socket connector!.

Sounds like you could do with a full system electrical test. This will test
continuity, insulation resistance, polarity, earth loop impedence etc.

That RCD tripping might have actually been saving your life all these years.
People who want to remove RCDs are often those most likely to be protected
by them! My RCDs never trip. (Unless I'm using my RCD tester to **** off my
TV watching daughter!)

Christian.