Hats and Helmets
Hats and Helmets are on layer 154. This is again a model layer which sits above the base model. If you look in the #head section of the _FOHuman.fo3d, you'll see some of these hats contain a "DisableLayer 7" before the attach command (they probably all should do - the ones that don't are my error). This "layer 7" refers to 157, the hair. Consider layer numbers in the _FOHuman.fo3d to be counting from 150. This DisableLayer command is there to basically "delete the hair", so it doesn't clash with the hat or helmet. This will probably need thinking about in future, because we're going to end up with the old "hats make you suddenly bald" problem.
~param 0 154 z
For layer 154, the value (z) can be :
5, 6, 9, 13-18 (from main 3D repo)
26-34 (my own test stuff)