Thanks for the accolade but "hero"? Steady on! I'm not really a hero but I did teach flying subjects and radio in the RAF. As a result, I find it easy to simplify explanations.
I thought about your problem with the regulator while driving home. (yes, it is boring when one is on one's own in the car). Obviously, I don't know the set up on your caravan but if it is the latest arrangement where the gas bottles feed into a common regulator and then off to the caravan interior, I seem to remember that there was an issue when first this arrangement came out.
It went something like this. If the outlets from the bottles are above the regulator as fitted, there was a problem. As it was now some time ago and my memory is not what it was, I put it out of my mind as it did not affect my caravan, I cannot remember exactly what the details were. Perhaps Trooper can come up with the answer. I have a feeling it was either on the Forum or in the Caravan Club Magazine. I know that doesn't solve your problem but it may point you in the right direction.
I may have the whole thing wrapped round my neck but your post did trigger something in my mind. Probably talking rubbish as usual.
It was nice to meet you and your good lady at Newark and put a face to a name.