Talk about jumping in at the deep end, massive gradients and enormous dynamic range to deal with. All the usual suspects are in there and easily recognisable, congratulations. When I eventually get around to taking and using data from different exposure times and accept the challenge to combine them, then I'll tackle this. Right now I know I'd struggle to balance it as well as you have achieved here with one set of exposures, so I'll wait and stick with lesser challenges. Great job Dave.
I have another order pending with the same co-ordinates - 60x60s + 60x30s + 60x20s + 60x10s. This should give plenty of data to experiment with for some HDR. I used the 'remove light pollution' tool in APP to handle the gradient.
I have just been comparing my effort against a Roger Clarke image of the same region using the same lens. Mine is on the right - still a ways to go. Roger Clark Orion Region