Im hardly a scripter (OMG! I CAN SCRIPT SIMPLE LOOPS AND PROPERTIES IN LUA :B) but, i have wondered why no one ever released a hat. I figured there was some problem, never looked at the code.
So, Decals are uploaded becuase they are packaged and the game recognizes them,
soooo, is there no such system inplace for the hats? (it makes little sense, being as how they have it for shirts, faces, maps, and addons)
I guess that it considers the hats the same as the arms, legs, ect.
Come to think of it, why not open mod capability for all the parts. We already have two of some details (hook or hand), a few more models never hurt right?