Really nice Pete
As to constructive criticism I don't pretend to be an expert on image processing but in my humble opinion I reckon there are a few finishing touches that could be made. I hope you don't mind but I had a little fiddle and applied what personally I like which is:
Add a bit more contrast, the image looks a little washed out.
Reduce the green channel slightly and up the blue a smidgen.
Reduce the star sizes to put more emphases on the nebula.
Cheers
Jo