Some new ideas there, and some I've tried ....
Checked the Inertia switch first of all, cos it's easy! It's in the ground return circuit from the fuel pump, which IS working, so...
Fuel is arriving at pressure, not known yet if high enough though.
Loss of compression would maybe happen on one cylinder, but you'd expect the others to keep doing something rather than all stopping firing at once, which is what originally happened. Still, I will get a comp tester and give it a whirl.
Sparks are happening on each of the three coil secondaries tested as you suggest, via the front bank of plug leads. Plugs all look good and unworn.
I haven't checked the injectors, which could all stop at once by way of a bad connection in the common supply, so the screwdriver idea is a good one I will try, thanks, and maybe the lamp/LED as well if I can find a way of connecting one. The plugs were all wet with fuel though, so it's difficult to see how that would happen if the injectors had stopped working.
Maybe a plastic bag has been sucked up and totally blocked the air inlet - that's my next line of enquiry. Air is the component not so far verified, and I'm just about out of other things to check
Thanks all Marco ni