I have contacted Rising Sun Performance in Ropley and also Abbey Motorsport, so just waiting for a response.
Here is a quick update -
I haven't had a proper chance to do anything on the car as I was called out to the Far East. I was wondering about the comments on this post about there being little chance of the car having a blown head gasket. The day before I left for the Far East I decided to have another look and took off the intake manifold and noticed oil coating the whole inside, also some oil pooling in the intake manifold collector. The pattern of oil showed that it seemed to be coming from the PCV hose. I removed it and the PCV valve and noticed oil dripping off the valve and a layer of oil in the tube.
I cleaned up the coating of oil, including the PCV valve and throttle valve (intake manifold side - no oil on the air intake side) and then fired up the engine. Still some grey/blue smoke, but not as bad, and after a few minutes there definately weren't any clouds of smoke. Tried the car again the next day and I assume the PCV valve was still drawing in oil, as there was now some smoke and it definately had a burning oil smell.
The oil and coolant levels haven't dropped and there is no contamination in the oil. The PCV valve, from what I know, has never been changed.
I have seen a few sites in the USA talking about the PCV valve and that it should be changed every year. Not sure if this is correct, but from what I have mentioned above does anyone think it is something as simple as PCV valve failure?
Unfortunately I can't check this until I am back, but I thought someone on here might know.