Thanks very much, Rick
Nearly there.. at long last
Just have to put that green/white switched live (ignition live?) to both orange/white wires on the heated seat switches (for the little green lamp whenever the seats are switched on) + tap into the sidelight circuit for the night-time illumination of the buttons (red/white wires), and finish off by hooking up the K-Bus.
Will have to wait for arrival of new battery to test. But,fingers crossed, all works.
Fair play for the How-To - wouldn't have had a hope otherwise (all those wires can look overwhelming to the uninitiated)!
Thanks again,
Karl.