The stamp seems to have the correct `c`s based on the earlier thread about the stahlhelm liners mark. I don`t think its dyed on both sides, maybe treated with something? As for the date perhaps it was made for an m17 stahlhelm? I seem to remember reading somewhere that the m16 was issued without a strap, where the m17 was issued with a strap?
Having said that, I havnt seen a strap with a makers mark before.
Its a nice helmet and even if the strap is a repro, its a nice one and will look better than most of the nasty copies around. Just my thoughts
Andy