Hi René,
The Face turned out excellent, congrats!
But I think you should check the cap: the black part above the visor (the stiff part of the cap) should be a slice of a cylinder; your current version tapers, like a segment of a cone.
You spent so much admirable effort into studying the face, with an excellent result; with just a little more of that on the cap I'm sure you'll nail that one too!
Cheers,
Adrian