Removing the shock and spring revealed the cause of the noise as the spring was rubbing against the upper link mounting.
There is a similar groove in the spring so I have got a pair of new springs.
The other problem i have found it that the upper link - where it connects to the hub - is completely seized solid. That is the steel tube in the bush is seized onto the bolt.
Going to remove the hub and get some heat on it.
Not sure if the spring rubbing is down to incorrect orientation of the spring or the siezed upper link.