I'd like to make a correction...  On closer inspection, I did see the "2" in the "21" from post #4. My prime suspicion was that the pin clasp at the bottom of the reverse was a dead giveaway, as was the pin hinge contruction at the top of the reverse.  Enlarging the images from posts #1 & #2, it also looks like a one - piece construction.  It is a well - made reproduction.   However... The 1939 Iron Cross with the maker mark "21" was manufactured by Gebrüder Godet & Co. Specifically, this maker mark is associated with the Iron Cross Second Class 1939.   https://www.treasurebunker.com/forums/index.php?/topic/3091-how-to-tell-if-a-iron-cross-1st-and-2nd-class-is-real-or-fake/  

S.Chriskelly is correct.

I’m not a fan. I don’t think these were made this way.

Not sure if these are of any use   https://stephentaylorhistorian.com/2020/06/19/german-ww2-7-92mm-headstamps-how-to-id-them-manufacturer-list/   https://cartridgecollectors.org/headstamp-codes/  

Thank you all for your replies.   I'm having a hard time trying to figure out what they say and what it means.   Just in the last couple of years I started collecting some WWI - WWII Japanese items, very fascinating stuff! I should have been buying it years ago.  

Jason,   Always wise to reach out to do research and ask questions before purchasing.. Just an FYI, an original SS helmet with single decal or even double decals for that matter are well into the many thousands of dollars... So if someone wants to sell an SS helmet for a cheaper price, it is too good to be true..   Buyer beware   Best    Leigh 

Obviously custom-made.  I can't tell if it's genuine.

From (formerly) "antique-photos.com"  

Many thanks ti "PaulR" and "Brig" for these examples of mounted KVMs.   https://www.worldmilitariaforum.com/forums/index.php?/topic/313911-mounted-examples-of-the-kvm/  

It looks Japanese.  It might be a civil defense helmet.

Both items are reproductions.  The "Frank & Reif Stuttgart" allgemeinesturmabzeichen is a well-known fake, albeit a well-made fake, and the EK1 is certainly not a Deschler product.   https://www.wehrmacht-awards.com/iron_cross/2nd_1st_class/1st_class/ironcross1.htm   https://www.warrelics.eu/forum/1939-eisernes-kreuz-forum/guide-collecting-iron-cross-1939-a-221753/  

Bonjour à tous. J'aimerais savoir quel âge a ce nionto que j'ai acheté 100 euros. Merci…