I checked the clutch switch while it was refusing to start, by putting a meter across the switch terminals. The switch worked perfectly every time, but the car still refused to start when I re-connected it. It may still be the problem. Next time, I'll short it out to prove it once & for all.
Earth to starter? I'd expect to hear at least a relay operating.
Immobiliser? The factory says it still allows it to crank.
Fuse? No idea! I've got no info on the electrics or the engine ( the handbook still refers to the 3L model.
Ian