Ok, first off you can't really make a helmet from sheet steel using the Pepakura pattern. At least not eactly. You need to learn (experiment) bending and shapin gthe sheet steel so you cn learn how large of a piece you can use for forming the dome. I think it can be done in 6 to 8 segments. Solder the pieces together once you have your shape. Sand it and paint it. If you need to weld it, that's fine but then the work to smooth it is more difficult, but way stronger. The none dome shaped pieces of the helmet are easily forme with Sheet steel. I Hot glued my sheet steel helmet together, but I had only intended to make a costume for limited use. Hot glue won't hold forever and it's not very tough. Hope this helps those new prop makers. For the Range finder... On the helmet I made for Halloween I installed an LED book light and used it to see with. Looked super cool, doesn't fit the range finder motif, but it looked neat-o.