I tend to agree on the coil pack being the main culprit. Youve done all your timing settings and checks so go backwards now. Tip of lead to the coil and eliminate the most basic thing first. I just finished of a villiers mk2 midg. Rebuilt the points assy completely with new insulators as it was grounding (common problem). Removed coil mounts and cleaned all the rust and crap then buffed the coil poles to shine and reassemble. Recheck spark still crappy and intermittent. Switched coil, same issue. Ok so I went to the ht lead spring pin. Seems ok from outside. Pull the pin, unscrew the spring from the ht lead, problem found. The screw had worn the lrad end and mashed the wire and basically slipped down the side of the lead touching insulator only. Simple fix cut the lead flush centred the wires with a spike and re centred the screw...bang beautuful blue spark....anyways not necessarily the same system but worth checking if the coil and points check out ok.
And btw I approach everything the same way as I do my HT also, and the 7 before it:)
