DONE!
Impellor had cracked but not disintegrated and was not spinning.
New waterpump with brass impellor fitted.
Timing belt kit and hydraulic tensioner fitted.
8 steady hours with a lunch, definatley quicker if I was to do it again.
Everything aligned perfectly, cranked engine twice by hand before starting, ran for 20 mins, quickly up to temp and stayed there, just need to keep an eye on the coolant level now (airlocks) and all is good. right?
Is there anything else I should watch?