Freelander 1 Radio Steering Wheel Controls

Hi Guys, I have just managed to find an original Visteon XQE000170PMA CD head unit from a slightly later Hippo (also fits a Disco I believe) and although the two plugs fit correctly and it all works perfectly, I have a third socket which presumeably accepts the loom from the steering wheel controls ..... which I cant seem to find despite having a good rummage behind the head unit

Has anyone got any pointers? Is there a pin out diagram for this somewhere on the interweb?

What? Hasn't anyone had a look behind their head unit then??