Question about armor textures (and where they are stored)

[t0neg0d]

So...

npc_types.texture ... global default... check
npc_types.[slotname]texture ... arms, legs, bracer, feet, hand... check

Here is where I am confused a bit:

Where is the chest armor texture stored?
You can set npc_type.texture to 3 (plate) and send a WearChange for chest to chain and the rest of the armor (if not set specifically) will stay as plate.
And... npc_types.helmtexture ?? I assume this where the helm texture is stored? If so, how does one go about showing helms on npcs? Setting helm texture via WearChange doesn't do anything (assuming this is due to some show helm flag?)

Thanks in advance!