I sadly do not have any tutorials on how to do those wings, but i still can explain how I did mine

I did the leathery part a darkest-neutral shade(
GW Shadow Grey) than my carapace (which is bright blue;
GW enchanted Blue) on a bleached bone(washed with greyphone sepia) skin.
I Then washed it with the
Gw blue wash.
That's all
You can do some highlights where the wing's leather is at it's highest.
I do think that gargoyles wings are tiny enough to look good even with only this level of details. For bigger wings, as
HT wings or Harpy's, ill do some highlights and some veiny stuff on them
I'll post a pic of one of my gargoyles when i'll get home to show you which kind of effect this method do. It's easy, fast and does quite well for wings of this scale
I'll try to post you the
Gw paint name i think would go nicely with your scheme if you want to try it

!
Oh and Happy to meet a new Nids lover