So today I got PMW started as the battery had been on charge.
I then took the car for a run to see if the overheating had been cured but had major problems after less than a mile. When I got the car home one of the heater pipes had come off letting all the coolant out so I had to fix that.
Next run of 8 miles on the test track was sort of OK as the car made it but continues to run with the temperature gauge at 3/4 and the electric fan on permanently. The new water pump hasn't improved things then.
In addition the car didn't run that well either, lacking power at times.
So, I think now it's over to Vicarage Motor Company for some professional help.