I have read the thread with great interest. My amateurish notes. Ivo, you say that in some attempts to smell unburned petrol. That means that petrol is being pumped. Still, my question, does the Morgan have some sort of gasoline pressurizer? That's why my 911 didn't start. Especially when it was warm. And that's how the problem started for you.
Here's another idea, I had a porsche 928 that wouldn't start because "temperature sensor 2" was broken. It thought the engine was warm when it was cold. Does the Plus 8 have a similar kind of sensor?
What I basically mean is if the ignition coil and all cables and plugs are ok, can it be a sensor problem?