Cheers Dan.

F-Super showed the codes for the injectors on in the ECU....turns out Solus can't read them, it can only re-enter them. Mind you, I'm still to check them against the injectors themselves.

That said......today I managed a leak-off test (of sorts....as best you can with a non-runner). No1 and no2 leaked no fuel off at all. No3 dribbled a tiny amount, and no4 was gushing it out. The fact I've got two invoices from previous garages saying no4 injector has failed plus what I've found has convinced me to order an injector (once I've confirmed the codes are right).
I'll put that in, and see how it goes from there. If everything else looks good I'll probably change the remaining two as well.....they can't have long left!

Thanks for your input.