Just in case you haven't sorted this yet. I've just done it to mine. Mine's a 51 Mk 1 CL. Main loom in car has the wiring right up to the socket in the front pillar. Doors don't have the wires though. I bought 2 front door looms from cars with leccy mirrors, and stripped out the wiring for the mirrors (had to work out which ones by looking at plug on mirrors and checking the wiring diagram). drivers side has some extra wiring (for switch). had to cut up the loom plug to get the connectors out so that I could fit them to my loom plug. (they're just a push fit). Wired it all in and they work fine!