Instructions:

1) Place folders in the module you want them to appear in.
2) Edit Module.ini and find the lines

load_resource = sarranid_helmets
and
load__resource = vaegir_helmets

change them to

load_mod_resource = sarranid_helmets
and
load_mod_resource = vaegir_helmets

save Module.ini (best to make a backup of Module.ini in case of of an error)

Alternatively you can replace the commonres files, making the helmets appear in all modules.
This isn't recommended unless you backup the originals.