Hi and thanks for all your input.
Hope all this lot may be relevant and not too boring
Went for another run out yesterday for about 10 miles on A roads. Pinking again on higher revs and under load on gradients. Retarded on the vernier for return journey (5 clicks and then another 5 as was still pinking a bit) only done about 50 miles, since I last knocked it back.
Car starts ok from cold and when warm just a quick flick of the starter.
I use tesco 99 RON all the time.
Vacuum advance moving point plates when pipe is sucked and holding vacuum.
Outer shaft has what feels like about 4 thou side movement (did have electronic ignition on car ages ago and couldn't notice any difference in how it ran compared to points).
Checked points. contacts good and gap still correct (last adjusted a few thou miles ago).
Outer shaft moves anti clock wise and returns, though not quite all the way (about 1mm short of rotational movement when looking down at the cams, if this makes sense). Have always kept it lubed with a few drops of oil down the top. Maybe centrifugal springs a bit weak?.
The rotor arm key is a bit worn, so the arm will turn a bit on the shaft, though is not loose as such, and arm appears to stay in the same position (has been a reliable arm, so reluctant to change it).
No strobe gun to see whats happening at different revs, though will get one if useful?.
I could strip dizzy down and see if any wear anywhere else, if that's useful?.
Cheers, Dave