Nice lid you have there, is this one of the fg that often pop up for sale or an abs version?
Typically the 'hero' version had a lower brow, 3 teeth per side, bubble lenses and 1 screw on the ears while the 'background' had a higher brow, 4 teeth per side flat lenses and 2 screws, although there were plenty of background lids with a lower brow like this. No 2 trooper helmets were really the same