Found this in a Japanese Surplus Store, it is very odd. It resembles a standard WWII Era US liner that has been retrofitted for JSDF use, but there doesn't seem to be a way to put any sort of metal shell over it the way it has been constructed. Any ideas? I know it is Japanese, the tag is hard to read in the photos but there are Katakana and Kanji printed on it.
![Early JGSDF Helmet? 20150618](https://i.servimg.com/u/f18/17/37/52/39/20150618.jpg)
![Early JGSDF Helmet? 20150619](https://i.servimg.com/u/f18/17/37/52/39/20150619.jpg)
![Early JGSDF Helmet? 20150620](https://i.servimg.com/u/f18/17/37/52/39/20150620.jpg)
![Early JGSDF Helmet? 20150621](https://i.servimg.com/u/f18/17/37/52/39/20150621.jpg)
![Early JGSDF Helmet? 20150622](https://i.servimg.com/u/f18/17/37/52/39/20150622.jpg)
![Early JGSDF Helmet? 20150618](https://i.servimg.com/u/f18/17/37/52/39/20150618.jpg)
![Early JGSDF Helmet? 20150619](https://i.servimg.com/u/f18/17/37/52/39/20150619.jpg)
![Early JGSDF Helmet? 20150620](https://i.servimg.com/u/f18/17/37/52/39/20150620.jpg)
![Early JGSDF Helmet? 20150621](https://i.servimg.com/u/f18/17/37/52/39/20150621.jpg)
![Early JGSDF Helmet? 20150622](https://i.servimg.com/u/f18/17/37/52/39/20150622.jpg)