John ,
Thanks for posting this , really like what you have done with this , nice fleshwork , would love to see this close up .
I agree with the comment ref varnish ..suggest satin and then build it up , you might like to have a look at Tamiya smoke as well for future helmets.
The painting of the helmet is great , , his clothing very effective ...how did you get that pattern ? , the shield ..well all I can say is what a job you have done ..spot on , is the idea taken from anything in particular or a mix or various sources ...
Its good to see your work on PF , always a pleasure to see how much you have improved since we first met ...well done mate.
Nap