Hats for the hatless.

I’ve been playing around with the bone merger tool in GMod, and I’m struck by how many of the various community models for TF2 (like Rebaccus’ Scout Mom or Chemical Alia’s genderbent classes) are completely incompatible or nigh-on incompatible with hats. What can I do to remedy this and adjust the position where hats would attach?

(Fun fact: oddly enough, the Scout version of the Pyromania goggles line up perfectly on Rebaccus’ Ms. Pauling.)