I've never seen this type of anchor marking before. The characters read "i-29-go【醫２９號】＊", so I suspect it might be a medical item.   ＊The character "i【醫】" is no longer in use and refers to medicine or a hospital. 　The character "go【號】" is no longer in use and indicates a number or designation. 　Note that "乕" is a variation of "虎".

Much better photos, and while I can't explain the anchor stamp, its not a navy helmet its a civil defense helmet. Its not a type 90 at all. I hope this helps some. A quick search of Japanese civil defense helmets will bring up many similar helmets. These were also made for factory workers and often bear insignia for specific companies.   Scott

Thank you Scott… the back story… the families grandfather was a WWI vet with the 29th, 2 combat stars.. his kids, the uncles, were army and marine vets in WWII… an entire box of stuff under the kids bed including 2 M 1917 helmets and cool gas mask..  The odd thing for me, is the rough cut brim…

Something is off about that helmet for sure. That hole does not conform to any type 90 fixture that I know of and there appears to be a tab or something on the inside in your last photo, again, not something you would see in a type 90. Can you take a couple more pics of the whole helmet, inside and out please.   Thanks, Scott

Ein Andrerer Foto  des Herzogin Cecilie of Mecklenburg-Schwerin Chefin des Dragoner Regiment König Fredrich III (2. Schlesisches) Nr. 8.

British miniature group with a US Navy Distinguished Service Medal

Just had this in a mixed bag of cloth. 

The S appears to be a rope?   After scrubbing the internet, I’ve found no helmets with this stamp.. the stamp appears to be a IJN insignia…the British used a similar anchor and rope insignia..   come on experts…  thanks much    

Many thanks for this pages 

Need help with this Type 90 what I thought was a dent in the front of the helmet, is actually a stamped S anchor…   can anyone ID this and translate the writing inside? thank you!

Yes The Netherlands, from left to right ;-    Officers' Cross  (Onderscheidingsteken voor Langdurige Dienst als officier) 20 years service    Military Performance Event Cross of the Royal Dutch Reserve Officers Association (Kruis van de Koninklijke Vereniging van Nederlandse Reserve-Officieren voor de Militaire Prestatietocht)     United Nations Korea Medal

Just a guess, - could have made in Egypt, India, Japan, Fiji, Singapore and many other areas where Commonwealth Forces served.    below are a a few pages from a book by Barry and Matthew O’Sullivan         Comparison with fabrics fro the different countries would  be a means to identify the origin of the garment.