I went back in the "Vectra" valley last weekend, a bit further to change the Suction Control Valves in the Denso diesel pump (a common problem)....
Pictures don't include the removal of all the injector pipes, common rail, electric turbo variable vane actuator and all electrical wiring loom connectors. .
Car passed the MOT and the emissions were "trace" ie detectable but not registered ie less than 0.01 smoke density

My back is just recovering !
Hopefully I can move on to Delorean stuff during my Christmas break. ...