Glad it's sorted - and not in the BECM at all...
Just to clarify a couple of things though... on the ignition wires you mentioned there was no power on them - which isn't the test I do on them. I use the continuity test or even the low range Ohm setting on the multimeter to check for continuity to ground, rather than a voltage. A lot of the things on the P38 (which I think is what confuses a lot of garages) are controlled by a connection to ground to activate something - rather than getting 12V to something.
Switchpacks... the actual window switchpack component is screwed into the back of the trim and can be removed and swapped over. Also the switch caps themselves come off if that's what are faded (again with the whole switchpack unscrewed from the trim) .
If you don't want the old switchpack, then I might be interested in it to add to my collection of ones to repair.