This will be my first post on the NMRIH forums, so i'll start with a hearty hello!
I have been following this mod for a good year, and have been impressed with the excellent direction and qualtiy content the team has maintained. I just finished watching the inventory system feature video, and noticed a small way I might help out. The scope lens on the M16 shown in said video is still visible as if shouldered even when the rifle is at rest in the idle animation. I learned this small trick from the Insurgency: Modern Infantry Combat development team, and thought I might pass it on. (I used to make skins for said mod under the name Walmarx ;D )
Scope lenses are simply a unique texture applied to the lens mesh, a basic circle. Hiding the transparent lens is as simple as cloning the lens mesh, and assigning the clone its own bone. During the Sighting in animation, transform the new mesh forward of the lense mesh, effectively hiding it. The opposite will bring it back into view for the Sighting out animation, of course hiding that awkward looking lense material. I can make some visual aides if anyone wants further explanation =D.