After spending my evening looking through wiring diagrams, it appears that early C70s have a window control switch pack, where there are 10 connection wires between the switch pack and the Drivers Door Module attached to the window motor, and there are no electronics inside the switch pack (apart from the switches and illumination LEDs).
C30/S40/V50s and late C70s have a window switch pack with some electronics in it, and only 3 connection wires to the DDM, where the information on which switches are being pressed or which LEDs to light is sent via the LINbus connection that is shared with the rear door module.
From looking at the connections on my window motor/Drivers Door Module, It appears that someone has fitted a late type Motor/DDM as a replacement, and naturally it is not compatible with the early type wiring or switch pack fitted in the car.
The fact that it still manages to operate to lower the windows to allow the roof to operate, when it's clearly the wrong module for the car, gives me some hope that if I can find a correct early unit from a breakers there is a chance that it might work without any messing around with 'software downloads'.
Now all of this is just theory and a bit of guesswork based on a few hours looking at diagrams and connector pinouts. If anyone with a bit more knowledge or experience can confirm (or deny) my assumptions, I would be most grateful!
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