Just to provide a brief update.
The car is running once again.
It seems it did run out of fuel and looks to have dragged a little water through to the pump. a light tap with a Brummagem Screwdriver and she's away again. (It's OK I was born in Birmingham, still regard it as home and am very fond/protective of the place!) So in the end, it really wasn't complicated at all - I'm just annoyed that given my roots, I didn't try this first!
Now I need to resolve the non working rear fog lights and number plate lights and it can get an MOT and I can then get to enjoy it a bit.
So thanks for all your help, and suggestions folks. It has been appreciated.