Sengoku Jidai: Warring States Period.
Myōchin Munehisa. [is yours authentic???]
Here's another Myouchin Munehisa; note the difference in signature:
Text accompanying the image above:
Phew .... that took a while!Among them, I had a helmet with the inscription Munehisa, it was quite wonderful.
On a line with rounded overall, in the quaint different again from the Kanto muscular helmet, It is thought to be due to the hand of excellent Workers.
There are many helmets with the inscription of Munehisa. It seems many workers have "ridden his name" [mei wo notta] and have have identified himself as Munehisa, but the other handwriting of the inscription was something you do not see too much. [ghp note: I think he's saying this particular helmet's mei is authentic, incomparable to the many "other" Munehisas.]
[EDIT: Your signature looks like it was inscribed in moist clay, not chisel-engraved in metal -- is that due to the quality of the photograph? .... ]
And here I thought it read "Made in Japan"....
"Much that once was, is lost. For none now live who remember it."
Thanks for the translation. I have no way of knowing if the signature is real. Knowing my luck, probably not but I paid very little for the kabuto so I don't think I could get hurt. I thought the signature appeared odd also.