Thanks for all the help on banding. I have several things to try but I don't think there is a definitive solution as each photo requires individual attention.
This was about the best colour in the sky I managed over the Xmas hols with many trips out and since then the East Coast has been going off now that back at work.
Was just about to head out to try and take some night sky shots but it clouded over. Clyde Muirshiel Park is meant to be a good spot with low light pollution so hoping to try soon