Hi just thinking about your misfire,I had a series 2 landrover brought to me a while back,the owner had purchased a electronic dizzy from Ebay that he wanted me to fit,I put it in set the timing it ran sweet until it got warm,then ran on two at best,let it cool back on four until warm,check timinig,valves,plugs,carb settings,nothing,so put old dizzy with points back in and ran fine,so looked at electronic dizzy then I found the fault it had been built using a standard black rotor arm,ordered the correct red rotor arm and away it went,might be worth a look to see if you have the correct rotor arm in your electronic dizzy.