Can we see a picture? Some exposed flat spot or ridge line is acceptable as you can clearly see it on screen with some troopers. Now if we are talking about a huge amount, you're going to need to shim.
I am requesting a Electronics sub-forum be created. There doesn't quite seem to be an appropriate section to post these type of threads currently. This would be a great place to showcase fan setups, voice f/x, etc.
Looks like you're replicating the "Move Along" Captain with the way the brow has been set. If that's the case, just review the SWAT threads and try to mimic. If you're just doing your own thing, I'd say you're off to a great start.
First troop of 2017 was at the Albany Devils game last Saturday evening. We had our biggest participation for this even ever this year and overall had a great time interacting with fans. Thank you, Kim and Dave Ramsey for the photos!
I would recommend at least putting a message telling people to "Please Login" or something to that effect. For the non-tech savy users, this could be helpful.
Helmets are easier since there's so many up closed pictures of screen worn helmets. When in doubt, go straight to source and never hurts to look at SWAT application threads.