Very Good Carl,
you seem to have a command of two of the scariest things known to painters;
- the airbrush
- female skin tones.
Skin tones are demanding in and of them selves, to do them with an airbrush is perceived as challenging (I feel as though its another tool to be mastered, a bit more complicated then a file or a brush, still a tool though) and a ladies skin tone needs a lighter touch, more subtle (which the airbrush is just perfect for)
Critiques? well, you've base coated it so far, done the primary blocking in of colour. Cant so much else.
As for the metals, well, how you handle them will be interesting.
Good start so far, it seems you have been doing this for a while now.
It would be great if you did an SBS with footnotes on using an airbrush. That would be encouraging to so many of us on here.
Cheers
Jamie