Good Evening Simon,
You have done a great job of pretty well losing those huge dust donuts in the background as you say. Probably wouldn't have noticed, but I took it upon myself as a challenge to have a good close look!
That set up I have always found a challenge, hence my earlier moan about a banding issue.
Hopefully with a new camera these issues will have gone away, provided that Mr A. has spat on his handkerchief and cleaned the optics as well.
That's a very fine image of a nice looking spiral galaxy, and I've just confirmed that I too have that data set. I think a close-up view, co-incidentally cropping out a few issues, may be the way ahead for me.
Well done,
Ray