No luck with the new condenser (although sent the wrong one but all the nearly the same electrically). Looked at the rotor arm looks almost new and distributor cap looks fine. Fitted another coil (one of another car I know works), hot wired to battery still no joy. Took each spark plug out in turn and grounded, cranked over and getting a spark on all four (not under load I know).
For a short time the engine would idle at around 900 rpm but most of the time dies and on occasion difficult to run under 2000 rpm.
Next I inserted a colour tune into cylinder NO1. Results interesting. Because the engine would not idle a put a brick on the accelerator pedal. Started and engine ran at 2000 rpm. The colour tune was orange so running very rich then after a short time turned blue with orange hints, correct mixture. Then I let the revs drop to see if it would idle and it did , colour now blue/colourless with just the odd orange flash, correct again for idle mixture. Even the exhaust had an almost an even beat but suddenly it started to misfire again.
Not put the colour tune in place of other plugs, big job as needed a mirror to see results, as in no1.
I'm now thinking there is a fuel and not electrical problem.
It has a Weber carb with manual choke. The choke appears not to work as need to pump the throttle to start from cold. When you pull out the control knob the choke butterfly does not rotate but stays in vertical position.
So thinking to much fuel/not enough air but the problem seems to be intermittent.
It is odd when I purchased the car the plugs were all very pale indicating a lean mixture and after no more than 200 miles the plugs are now black with soot plus there is the misfire.
Further help needed