Well, well, started cold fine, had a good run out today, stopped for coffee and cake (back at home again I'm not reckless) and 45 mins later she would not start.
Started eventually but was missing and a couple of back fires. Was wondering about that new distributor cap so whipped it off, studied the inside which looked fine but noticed a bit of soot on rotor arm spring contact to coil. Put a used rotor arm in from spares box, showed it the ignition key and it burst into life. Roared around the lanes again. Back home for more coffee and cake and she started again first spin of the starter 45 mins later.
That spare rotor arm was in the car when the trouble first occurred. Ah well, the ignition circuit has had some love and attention and a reassuring compression test has been done. Thankfully I did not start messing around with those needles and the mixture!
Thanks to all, happy motoring.
Alan