Hello moggyjim,
There are no left hand threads within the clutch system.
The big difficulty is with the “pinch bolt” which tightens the clutch mechanism onto the shaft. Undo this first on disassembly and tighten it last on re assembly. Do not over tighten as over tightening will snap the cast lugs through which the bolt passes and repair is difficult to effect with either weld or braze. There is a bronze bearing in the clutch drum at the back of the clutch which can be greased via the grease nipple within the tube of the clutch shaft. Ensure this is clear for future greasing otherwise a loud dinging noise will be emitted when the clutch engages. Split the joining link on the clutch drum drive chain to remove drum.
Good luck with it–Steve