I'd have another go at processing this image John. All the channels are black clipped (see attachment), hence you've lost some valuable data (and the image is rather dark). It maybe that the data isn't good enough to stretch hard without introducing considerable noise. If this is the case, longer subs at a lower ISO maybe the answer. Look forward to seeing more.
Jase, there is no fooling you is there? Really appreciate the feedcak though...
You are quite right the noise comes up if I don't clip a little. I will try once more but I did spend quite a while on trying to optimise - and felt I had got to a reasonable result with the nebulosity mid tones - the bright stars are bloated and the faint detail showed noise.
I think I will need to use the multi-zone technique or as you say shoot at lower iso for longer.
