OK, so back in the lovely weather UK :rolleyes:

Anyway now had a chance to try the clutch pump and open the bleed and to be honest no big bang of fluid just a steady flow once open I assume this is gravity rather than pressure still being applied ?

So unless there is something else to try I guess next is to drop the oil and replace with semi then ultimately move on to the plates /springs approach after that.

Thanks again for all the input

If you have tried the oil I would take the time to consider the clutch plates, both priction and plain plates. I had really bad slip on another bike and changing these sorted it out. However, I did use OEM plates and made sure the stack height was spot on. (which is loads of fun and means buying a new tool, which is always cool)