Hi Daniel!
My two cents if it's worth something.
It's a Showato, not a Nihonto.
How it got a Torokusho especially for a Showato....
And if the Torokusho is original the sword has not left Japan on a legal way.
Handmade yes but not in a traditional way from Tamahagane,
Especially with a Seki stamp on it.
And that Nakago doesn't seem to belong in Toko Taikan.
I may be wrong so correct me if I am!
Best regards, John