[Mark S]

Ok, good to know the facts.

I know George, and I know that he would never knowlingly sell something that was not correct, and from what you have said, you know that as well.

I have used George for a fair bit of work, including a replacement engine (like yourself) cambelts and fitting piper cams amongst other stuff.
He is the only guy I know who bends over backwards for people as goodwill to keep them happy in/after event of problems, even when its not Georges fault.

You will not find a more reasonable person than George to deal with, but you do need to communicate live chat - ie the telephone any issues with him and trust him.

It is fair that george will need to see the engine and prove to himself that its faulty, if it is.
Your best route is to chat (humbly) to George and just make sure you have covered all angles and explore possibilities, proving between yourselves and eliminating any other possibilties.
George is a nice guy and very helpfull.
Like me George is old school, so chat on the phone.

Do this first and I am sure things will get resolved.

On another note of Georges hangups with continued supply of mg parts, I fully understand and have made comment to George before about the viability of continuing selling Rover/MG spares. Looking at the demographic profile, business model and long term (even short term) viablity, it sadly seems that it is not a profitably way forward. I personally feel George would be a loss in the MG scene, but passion does not put bread on the table.