Thank you all for your opinions, I really appreciate it
I see it was a good decision to ask here in the forum. I didn‘t know that blanc JzP was against the regulations but that it was accepted. I really thought it was a special regulation for parades, because Helmets like this have been sold so many times on military auctions with prior professional article inspection.
@John: Thank you for the negotiation tip, I will take it into account. You have an awesome collection of Lobster-Helmets, I love it
@Bruno: Thank you very much for the great hint with the Museum-Depot no. May I ask how you figured this out?