I dont think the straps need to be on the inside at all, because then if you need a quick adjustment (Like I saw you do a few times at CIV) it would be a tad more difficult.
His armor is aluminum, hard core tough stuff, they hammered it out themselves (The DSG, Dune Sea Garrison).
I would re-glue the visor to the helmet, because you are squinting and the teeth and mandibles are farther apart.
I like it dude, keep it up, I gotta troop with all you mandos when mine is done...say SDCC??