Hey Man
That is looking awesome.
only suggestion I could give is:
You might want to raise it up a bit with a few more layers of clay before adding the detail. Its thin. It's too close to the cast of your head and might not fit when casted
I learned that the hard way on my first helmet. Live and learn I guess.
You'll need some space in there for hinges and other gizmos too.
hope this makes sense