Thank you for this hint. I never got a handbook with the car and as a search doesn't show the content of the handbooks - I didn't look them up so far. Good hint.
As the green handbook for a Morgan 4/4 with CVH is available on Amazon I just ordered one.

I also found a very interesting information on the Gomog handbooks on the ignition timing.
The Ford CVH manual says 12° BTDC - but says nothing about using 8° BTDC for unleaded fuel.

As the garage that did the technical inspection used the Ford manual - I wonder if this might be adding to the startup issue.....