Lord Valefor
Super Freak
. . . the customizer in me would try to file/sand down the top half of the mask along the bottom ridge (and concentrating more on the mouth/front). Then I'd see how it looks when re-attached to the bottom half. But before gluing it back together (hopefully with a shorter mouth), I'd try to slice off the tube/tusk parts on the bottom half and glue them at a more accurate angle. That's where the unnecessary seam in the tusk would actually be a good thing; I'd just fill it in, sand it smooth, and paint a semi-gloss black over it. Done; seamless tubes, corrected tusks, and shorter mouth.
In fact, having access to the blank head inside of the mask might even allow for some way to loosen up the neck and provide more mobility. If I ever see one of these unglued helmets going for a fair price, I'm giving it a shot.
But the dome throws off the look of the figure as much as the tusks