You have a similar system to mine, including the carb heater. I have changed those metal capped plug connectors for the synthetic ones. The HT leads simply unscrew from sockets on the caps and the coils once you slide back the rubber gaiters. Have you had a check of the points gaps. These can get pitted/burnt on the faces and reduce efficiency. It may seem to be to be a big job but it isn't, but the best thing is to remove the engine/propeller combination to a bench. All you have to do is remove the recoil starter and lay it on the wing within a clean rag. Match mark those leads where they plug into the nylon connector. remove the carb assembly including the rubber interconnecting sleeve and lay on the wing(empty the bowl first) cover the induction port on the engine with a clean cloth to prevent ingress of debris. I bought a flywheel removal tool from Skydrive for changing the points (they will let you borrow one for the job) A fan holding tool is also needed for removing the belt. There are shims that set the tension on the fan belt shaft - ensure you take note of the way that these are placed below the retaining nut. The nylon fan slides on to a Woodruff key on the shaft so take care that that does not drop into oblivion. Remove the four bolts that slide through the Lord mounts and lift off the engine. Once you get the flywheel retaining nut off. Fit the removal tool and extract the flywheel. It fits on to a taper on the shaft and comes off with a crack - don't be alarmed. The whole points, coils and condensers are exposed for inspection.
This may appear complicated when read but is very simple to do. I was apprehensive when first doing this but really there is nothing to it.
If I lived nearer I would come down there and go through the process with you.