Hi Brendan,
Yes, go and see your local golf course as they are sure to be able to put you on to who they use to do their machines.
I'm getting the impression you still are not understanding what I'm trying to convey to you in regards to the clutch housing running true or not as that is a major part of whether the clutch is grabbing only on a partial part of the revolution when the drive is disengaged. Regardless of that it seems that your clutch cone is slightly out of adjustment and will require the clutch fork adjusting screw to be wound in a bit more, but it can only be wound in to the point where when the drive is engaged that they is a slight amount of clearance between the fork and thrust pad. Also I would make sure that all the clutch parts and associated pieces are well lubricated as that's essential for smooth clutch operation.
Cheers,
BB