I'm really sorry, I totally forgot about this thread.
I'm assuming that you already know that all the buttons do is send current through different resistors depending on what button you are pressing, therefore changing the voltage which the module interprets and inputs and sends to he MFSW relay? The main module (in the LEFT) button module translates all these voltages into a LIN-BUS signal that talks to the MFSW module (Multifunction Steering Wheel).
So, on the LEFThand module, you have 3 wires coming IN from the clock spring and going to the 5 pin connector. I believe that is what you are asking for?
1) The two black wires (pin 4 and 5) operate the horn. Basically one is sending out +ve and the other is a ground. When the horn is pressed, the little metal "arms" on the back of the airbag complete the circuit and this tells the module to send the "horn" signal over lin-bus.
2) The yellow wire (pin 3 on the left connector you've pictured above, goes to pin 5 on the STEERING WHEEL side of the clock spring) is the lin-bus or "data" wire going to the relay/controller.
3) The brown wire (pin 2 on the left connector you've pictured above, goes to pin 4 on the STEERING WHEEL side of the clock spring) is ground.
4) The black/brown wire is "ignition positive" signal. Also called 15a or A20 in the MKIV. It is pin 1 on the left connector you've pictured above and it goes to pin 3 on the STEERING WHEEL side of the clock spring.
You only need 4 wires going to the second set of switches. You have:
1) Ground
2) Illumination
3) +ve for each of the two up/down toggle switches (volume up and down/seek forward and back)
It sounds like you don't need that pin-out?
I hope that is what you are looking for? If it isn't let me know and I'll try to give you the info you need...
Cheers,
-Chris