I have watched this thread with interest. I have not handled the helmet, and my knowledge of cavalry helmets is relatively limited. Therefore I have no opinion on its authenticity. Posking, you are not doing yourself any favors here. While nobody can claim to know everything, the members here and those who frequent this site probably represent the greatest body of knowledge concerning pickelhauben on the planet. I would suggest you review Adler's Collection thread before insulting and alienating him more than you already have. Aside from the considerable financial investment involved in assembling such a collection, the research, acquisition of knowledge and experience represent an equal or greater investment. And you come here begging for some of that painstakingly gained knowledge and behave badly when you don't like what you hear.
I collect firearms, mainly. I have owned prototypes and tool room experimentals, some very rare weapons. Those guns were like boats: the two happiest days of your life are the day you buy it and the day you sell it. I know you are desperate for your helmet to be authenticated and have other collectors beating a path to your door trying to shower you with gazillions of dollars to buy it, but don't hold your breath waiting. Unless some authenticating documentation or photographs surface, the jury will always be out. And if the helmet is so obscure nobody knows what it is, then it's merely a curiosity.
I suggest you take a "time out", and return with some courtesy and respect.
Consider your ways.
Steve
PS I would also suggest you refrain from using words like "stupid" when referring to other members' opinions. It just demeans you further.