An update for anyone still following this.
In an attempt to cure the problem my series 3 landy was having with a misfire type hesitation whilst accelerating above 20 mph, I have replaced the points, stripped and cleaned the carb and fitted a service kit, checked and reset the timing and swore a lot. After all that, it still hesitated /misfired, though not as bad. I have now fitted an Accuspark electronic module in place of the points and condenser and this seems to have done the trick (knock on wood). I fitted a new coil a few months ago so I didn't bother getting the Accuspark one, which I'm now regretting. The instructions for the module provide a couple of tests which need to be done to make sure you have the right coil, failure of the module due to the wrong coil invalidates the warranty. One of the tests says to measure the resistance of the coil, it should be 3 ohms or more. Now, how do you measure this? Is it simply a question of connecting the red and black leads of the meter to the + & - of the coil? If so, I have a problem cos mine reads 1.2 ohm. The thing fires up and runs well but I'm a bit worried about burning out the ignition module.
Col