Steven Campbell wrote:

The top wire (4pr) runs from one side of the loft to the other and into
another junction box. From there the wire changes to proper telephone cable
wire and runs into my bedroom. Which I thought was the BT master socket but
since part of the run is in 4pr wire I doubt very much now that it is.
The bottom wire ran all the way down to the dining room and terminated in
what looked like a small accessory socket!

OK, one of those should be the master ond one a secondary. Does either
of them have a BT logo on it? If so, that's almost certainly the master.
If you can take the front off the socket, the master will have a
capacitor, resistor and surge supressor on the back.

If you want to make it look "normal", then you need the wire to go from
the junction box to the master socket, which must have a BT logo, using
standard phone cable. There should be no branches before the master
socket.
Since it sounds like neither socket is a linebox (with a split across
the middle), then the extension to the other room should be plugged into
the front of the master socket.

Also as the line isn't on a proper pair, it won't do ADSL speed
any good.

I don't follow you re the line on a proper pair?


From your picture, the line is on the orange and blue wires, which
aren't a pair. Each wire is twisted with its corresponding white: blue
with white-blue, orange with white-orange, green with white-green. The
twisting reduces interference that can slow down ADSL connections - two
wires from different pairs aren't twisted with each other, removing this
advantage.

Mike