I could probably scan it for you, but honestly I wouldn't want you to risk your original piece, so regardless of who you choose I think you should mold the piece and send a cast off for scanning, unless you find a place cheap enough near you, where you can go along for the scanning session. Don't let the original piece out of your sight - I mainly don't trust the postal system, in case it gets lost. That would be a real shame and loss.
Another thing... the two sides of the helmet aren't exactly identical, so mirroring the scanned piece to print out both sides may not generate an accurate helmet, but may be good enough for a decent looking helmet, based on an authentic casting. However, there was a guy selling Altmanns prototype casts that was claimed to have come off an original and if a deal could be made with him for the other side of the helmet, then the two can be merged digitally before creating the physical piece. At least that's another option.
