Could Use Some Help With This Helmet

[RonR]

This Japanese Helmet is unfortunately missing the Star, but it has some Japanese characters on scratched into the paint on both sides.

Would really like to know what this means and any help would be appreciated.

Lots of shots of the Helmet.

Profile view:

[RonR]

Left side view:

[RonR]

Right side view:

[RonR]

Front view:

[RonR]

Rear view:

[RonR]

Top view:

[RonR]

Closer of the writing on the left side:

[RonR]

Also on the left side:

[RonR]

Writing on the right side closer:

[RonR]

Also on the right side:

[RonR]

Inside view straps in:

[RonR]

Straps out:

[RonR]

Liner band mark:

[RonR]

Shell stamps:

[Edokko]

The three chararcter Kanji marked on the sides reads to be a name "Misoya （見楚谷）”、but the single Kanji marked near the name is not Japanese Kanji, if it is a Kanji at all.
The mark on the inside of the brim is "sho （小）”refering to the size "small".