Hi there Remus. For the muffs I used various pieces of plastic. I have tried alot of different items, but the important part is finding plastic that is the right thickness. From there I use an allen wrench to trace the 8 sided shape of the muff. I cut that out. Then there needs to be an angle to the top, so that is tapered. I go around the edges of the muff wth a razor, cutting an angle to the edges. Its very difficult to get all the edges and each side to match exactly. Alot of trial and error! After that, I shave the raised sides of the helmet off, to create a flat area, then i carefully position each muff, and glue it on and paint. Again very tricky to get them exactly to match on each side of the helmet. I have found that many helmets are not exactly symmetrical, which makes it really hard to get the muffs to match on each side. Good luck!!
