I've been fiddling with this for days now and I don't think I can do any more. 300 minutes in 5 min subs over 2 nights. I have had trouble exactly aligning the two sets of data in IP so some of the stars are not quite round. Also I cant seem to get the colour of the central parts of the M galaxies quite right, seem to be a bit purple and I think I've lost a bit of star colour. Anyway here it is. NP101, SBIG 4000XCM, AP Mach 1GTO, IP and CS3.
Thanks for that Greg, I've spent hours fiddling and when you mention magenta things became obvious. Herewith the result (for better or worse), I'm still not sure it's exactly right though.
Thanks everyone for your comments. One of the things I learnt from this image is that it takes an awful lot of time and effort to get something approaching half decent. I also think I need to choose my targets better, things with more scale for my focal length.