Japanese helmet - please help with translation??

[anton67]

Hello,
I posted this helmet a little while back.
Now that I have it in hand I am posting pics of the writing.
Can anyone please help with translation???
Thank you in advance.

[GHP]

Scratched: Deguchi Shou-i
2LT Deguchi

Inked: Deguchi

Crayon: Yoshihara

White paint: Dai (size large).

[anton67]

So would Deguchi be his last name?
And would Shou-i be his first name?
Also what if any significance is the Crayon: Yoshihara?
Thank you very much for the translation.