Tow socket electrics

[ianl1]

So i thought i would look at my tow electrics socket on my 97 defender 90 300tdi which has never worked properly

some investigation has shown its wired wrong with ground, fog, brake all on the wrong pins

ive looked in the rear right corner where the tow electrics hook up point connectors are, and this is where im getting a bit confused. 

each black connector has two wires into the bottom of it and two holes in the top to accept bullet crimps, is this the feed into the connector and the feed out to the existing light, and the tow wiring goes in the spare holes? Or the feed in and the feed out to the tow socket with the car lights fed separately ?

The right hand tail /stop lamp is fed seperatly from the loom, and the fog light uses the 3rd hole in its conector , this is what makes me think that it is a feed to the tow socket, as if not where does the 3rd fog wire go? but if so, where do the wires change from land rover colours to tow socket colours/cable?

also are the two wires fixed in the bottom of the connector, or are they crimps plugged in? Ie should i be able to pull a wire out the bottom of the connector