Removed the manifold and ensured the head face & manifold mounting face were clean and flat. The manifold did have one bead of weld on it which I filed off, it also had a very minor bend along its length less than 0.5mm so should be good.
Fitted gasket & manifold and re ran the engine; there was a little smoke at first but then things settled down - I think its fine now:
Minor leak from the water hose take off for the heater - tightened.
The water gauge appears to be reading low, at least different from the ECU.
Addendum, got the fuel gauge working too - it needed another 5 litres of juice in the tank and tap the tank/rock the car to unstick the float - 5 litres is showing 1/8th of a tank right now which is a little low but good enough for now.
All seems fine & ready for someone who knows what they are doing to tune it for me.
