I'm still rather favouring the ignition amplifier, they breakdown and die and that is the symptoms you have described Ivo, we have established clearly with your checks that she is fuelling and the coil ist in ordnung and all the leads have been renewed/checked.
Another check I would carry out to eliminate this or prove it is to remove the distributor cap completely and check very carefully in good light conditions to check for any signs of carbon tracking interior and exterior. I once had this on my Scimitar (V6) and it started off with the odd misfire and finally manifested itself in a non start after a very fast hot run on the Autobahn in Germany.
It just shorted out the coil input to the distributor straight to ground/earth.
Good luck.
