Having done a tiny bit of fibreglassing inside the skull cap of it last Sunday (and having part fibreglassed a lower leg piece through the week) I spent a few hours fibreglassing the rest of the inside of the helmet - no need to do the outside.
I've never worked with fibreglass before and it's flddly, yet effective. For the bits where human hand simple can't touch and apply it accurately (inside the brow of the helm, for instance) I'm going to fill it with spray expanding foam. It took a few hours (and a lot of mess) to get the entirety of the inside of the helmet covered with fibreglass and resin but it eventually cured and hardened to the point where I could hit the next stage. Photographs from yesterdays efforts are below; At the end of the day I had a completely fibreglassed helmet coated with the exterior coated completely with p38. Now just to sand it with Hand sender and Dremel for the details, which is the aim of Sunday.