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… 

A friend of mines son bought this and was told it was ww2 Japanese.  It has a different liner and chinstrap than the original that I have. Can you tell me the approximate year and nationality of this please? Thanks Mark

Standard German Army eagle of the day. 

I see many photos has a stamp on the back similar to this why is it so?

He looks like a Hauptfeldwebel“Spieß” to me.   At least he has a "Kolbenringe" up his sleeve.

The application of the NSDAP Insignia done literally overnight upon Anschluss.

Yep I knew the decals were fake. I was just curious if the helmet was wartime or not or German?....thanks What makes it a Czechoslovakian  helmet??

The ones you got are Weimar Era Reichsmarine Buttons as it has that rather plain Eagle stamp ie not a NSDAP Eagle. The WWI Pre WWI had the Imperial Crown above the Anchor on the front, this feature was dropped after the war when the Navy was allowed to reform in the 20s,  albeit drastically reduced.   The Eagle marking  I think starts to be used then, the  Kriegsmarine Buttons  when they are proclaimed from 1935 or so on, didn't have this Eagle  marking anymore as far as we can see. Though with out a doubt these Weimar ones continued to be worn during the 30s well into WWII as stocks permitted as they have the same front design as the newly made ones of the TR period   Here's another example, albeit a different style,with the Eagle more defined, I think its for a Peacoat???.

Polizei Grun.