Check list so far

New belts - done
New shinko tyres - done
Brakes bled - done
New battery fitted - done
Start bike - done, oh what a lovely sound

But, now find that clutch lever comes all the way back to the bar without actually activating clutch

Where do I start to diagnose this one? any clues? Feels like I have lost pressure in the system. Was alright when the bike was put away 9 months ago and there are no obvious leaks from the bike

Have seen the mater cylinder rebuild notes in FAQ. Is it likely that the problem lies here?

no obvious leaks bleed it. Works better with the master cylinder off.Also the lever arm adjusters back out frequently

I'm having a similar experience ... I think my slave might be done. I've just order new slave internals, so we'll see. I've bled it a couple times, and it feels ok ... until I start riding. It feels like it's only the last half of the lever pull that anything happens. I'm not sure, but the clutch sounds a bit more rattly than before too. But maybe that's just me. We'll see what happens with the slave bits. The master is only a couple years old, so I don't think that's it.

Take the clutch apart and clean everything then check the order of plates and the stack height

If you have no fluid leaks then you have air at the master.You will have to take the master off the bike to get the air out, there really is no other way to do it