Thanks for super fast response Arnoux.
I had played with the adjustments top and bottom.
I've just had another "play", checking the fluid level in the reservoir.
(incidentally there is no window on the clutch master cylinder)
All looked good, as detailed. No cracks in the actuator arm.
I bled the system as described, and no bubbles appeared; despite spending 20 minutes tapping and moving the pipe!
Whilst the lever still doesn't reach the h'bar, I'm not that fussed as when riding with one finger on the clutch, the rest of my fingers are struck before it hits this physical stop mentioned in first post.
I'm set to ride it in my first trial at the weekend, and will let you know if I suffer because of it!
Cheers again,
Lord Lanky.