Still dead this morning. Bother.
I suppose no other member has suffered similarly, it's clearly a rare failure. One more example of the joy of running 15 year old cars. Modern cars are designed to last 7 years without much trouble, then get scrapped. After 15 years lots of things fail.Car relays are wonerful things, function for years in a robust environment (temperature, vibration) without complaint, but fail eventually.
The car is a PFL 2000 petrol manual CDX. I presume it has the later models wiring, but am not sure because the front switches seem to be boxed with other relays and in the door. Also the S37 (LH) box is labelled driver's door electric window witxh assembly. My car is RHD. Is there a language problem here?
Some contradictions there...
Wiring diagram, assuming haynes, is LHD but does detail RHD differences. You are correct in working to the 'later' diagrams... facelift cars also broadly follow the later diagrams but with some detailed differences. That said, I have found them accurate enough to work through items although I now have the Vauxhall facelift wiring diagrams, so only tend to use Haynes as a quick reference or for researching queries here...
You say the car is PFL, but on a W plate it will be either Mid face lift, with the grill in the front bumper and window switches on the centre console, or Face lift with the grill on the bonnet and the switches on the drivers door... I know you have, and still do, own several Omegas, so I stress the above to remove any ambiguity rather than trying to be an arse

I cannot help but wonder if your car has been fitted with the wrong door loom, either by virtue of a replacement door or to solve a previous issue

The wood in the rear doors certainly suggests that the previous owner wasn't adverse to improvising
