Hey Matt, nice shot, is this really your first Joop? I was working with the neximage for 2-3 months last year before I got anything near this good
and the conditions were better too. You've got the colour worked out, if the seeing settles we can expect something really spectacular.
One tip- drop your exposure time to 1/10th or 1/15 s so you can reduce your gain. You'll remove a heck of a lot of grain and hopefully sharper detail.
cheers,