DaveG - thanks for the offer I will send you a PM in the next couple of days.
Jerry - problems with no knowledge of the root cause are always much worse than one's you can see and work your way out of. Wiring on Slow Monster or carbs on your 750 I'd rather have this clutch issue.
Regardless all support (moral or material) is welcome.
Today was overall good but with a few lingering concerns.
Studying Luddite's post I worked out I do not need to separate the clutch basket but rather remove the LH side casing (with the clutch basket still attached) in order to get to the kick starter return spring.
The casing castings are really a work of art. They are of a material that takes a polish really well and are elegantly made, definitely no thicker than they absolutely have to be. The problem with this is that there is nowhere to apply any force to break the gasket seal, no leverage points, and no overhanging lips at the joint to tap with a soft-faced hammer to get the gasket to part.
I must have spent half an hour tapping all around the joint face with a dead blow hammer and the casing moved not a micron. I tried snipe nosed mole grips in the recesses for the retaining screws with the same result.
I realised I needed a puller but the only possible points to attach it to were 4 bosses cast into the clutch casing to mount the outer cover. There were 3 problems with this:
1. the threads in the bosses were only M5; and,
2. the outer cover casting is double curvature so the boss heads were in 4 different fore and aft plains relative to the only solid bit I could use to press against i.e. the gearbox input shaft; and,
3. the 2 front and 2 rear bosses were c200mm apart.
I never throw anything away and eventually, I found 2 bits of 30mm x 4mm steel strip and made this up:
I originally intended to make this in one piece but did not have any suitable material. Being forced into making it in bits actually was a Godsend and made it possible. I cut and drilled the two vertical bits and screwed them to the casing, then made the cross piece roughly drilling it 10mm and welding an M10 nut to the clutch side. The Allen screw was then aligned with the gearbox shaft and the cross piece tacked in place. The welding is not my finest effort but I blame the fact that the wire spool had been exposed to moisture and the wire was all corroded and consequently the arc was very intermittent.
I wound in the m10 Allen bolt very carefully hoping that the 5 mm screws would not pull out of the bosses and when I could not bear to put any more pressure on the Allen key there was a dull crack, much like a fine irreplaceable casting breaking, fortunately, it was only the gasket cement giving way.
The inner LH case is off and to prove it here is a picture:
snagit