Hi James, found this .OBJ file over at the RPF! Its as close as I could get to what you are after.
Hope it works for you and as always check the sizing suits your needs and post some pics if and when you print it. There are 3 versions here, let me know which one suits and I'll cut it up to print if you like? Cheers Jace
Thanks to Janelle Redding for providing the pics of an an awesome looking completed helmet!