Started Last weekend (end of January) on Ironman using the 405th method of Pepakura - Fiberglass - Bodyfiller - Paint .. to make it look alright.. i hope i do it justice..
Note, i have done a lot more than just the helm but until i have the torso assembled right im not posting a photo on here.
try altering the dimensions in pep. theres a scaling option measure your head... then work out an box that your head would fit it and enter those dimensions