Hi Mike,
I'd tried that and it still wasn't releasing, however I think I've solved the problem! The anti judder washer (I think thats what its called) was fitted upside down!! I've now refitted it and the clutch seems to release normally, still seems a little draggy but I suspect once its been in use a bit it will free off.
Thanks for your inputs though, it was your prompt about the ball bearing that made me triple check it was there and that was when I realised the anti judder shim was in wrong!!
Thanks again Mike
Paul