I'm trying to bypass the standard helm fix and go straight to the source.
The standard helm fix is to extract all the "Item\ObjectComponents\Head" m2s and skins. Then to copy and rename the Race/Gender your converting to into the Race/Gender your converting from.
I'm thinking that the game knows exactly how and where to look if it needs a helmet model for a particular Race/Gender. If I am playing a Human Male and I equip a helmet. Somewhere there must be a line of information saying "I'm playing a Human Male. Look to the "Item\ObjectComponents\Head" folder and use HuM files."
If that is how it works then it would eliminate the need to copy and rename all those m2 and skins potentially saving about 3-4mb before compacting in a mpq creator.