I think it's quite a nice image, Paul, but a little noisy as you said. You could improve that with some noise reduction in processing but there are limits to how much NR you can do before losing sharpness.
As Mike said, the ideal solution is to get more data and maybe longer subs. What you want is subs long enough that read noise from the camera is not significant. How long that is depends on your camera parameters and sky brightness. It's not that hard to determine from a couple of example subs whether you're read noise limited or not. Have a look at the method proposed here:
http://www.iceinspace.com.au/forum/s...d.php?t=117010
Cheers,
Rick.