Having just recently procerssed a high res version of this same field I am pretty familiar with it Dennis and this is an excellent portrait mate
.
Looks like you have used a filter that has produced a slight mottling in the nebulosity, I am thinking deconvolution or something? When I see this it always makes me kinda question the reality of the details in places...? Do you know what I mean? It is clearly high res but that uniform shapped fine mottling looks to be caused by the processing...? It's just a feeling and I may be wrong
...I was wrong once but it was back when I got married (just kidding
).
Still a great shot regardless
Mik