Thanks for all this help guys. I'm quite confident with it now. I
have bought a new socket (could only get the screw type though) and
know exactly what to do with the wires.

My only concern is getting a shock or shorting everything out! I plan
to cute the white sheath away very carefully and then to deal with each
wire individually. Can I get a shock in this way?

Naturally, I'd remove the lower half of the master socket if I had the
modern variety but alas I have the older style (in a really horrid
brass finish)!

I may ask BT about installing a new master socket but if it costs it
won't be worth my while (except for the fact that I know my new socket
installation will be shock/short proof and that I'll have a nice new
white socket in the lounge)!

If anybody has any further observations they would be welcome.

Thanks again,

Daz