Assistance required: Sword certificate translation and general information

[g2nightmare]

Hello. I have what I believe to be a Tachi from 1447 signed by Bishu Osafune Norimitsu.

 

I would like to know if anyone could kindly translate the certificate to help me confirm this and possibly share their knowledge about this sword. I've attached some other images of related texts - if possible could someone explain what these texts show and if they are important to the sword's history?

 

Please, assume that I am a complete sword noob (I am) and I don't know much of anything about this sword or Japanese history.

 

Thank you!

[Ray Singer]

NBTHK Hozon kanteisho 

 

Bishu Osafune Norimitsu 

 

Bunan San nen ni gatsu hi (a day in the second month of 1446)

[g2nightmare]

Thank you very much for your reply. Do you have any additional information about the translation? Specifically about NBTHK Dozen kanteisho, and about Bishu Osafune Norimitsu. I tried some Google searches and it was confusing. Is NBTHK a certificate authority and is it legitimate in your opinion? I want to know what generation of Norimitsu made this sword and what kind of quality it is.

[Ray Singer]

NBTHK is the leading authority (in terms of an organization) for issuing of kanteisho. There was more than one Osafune Norimitsu working at that time. They did not specify which individual or generation was responsible for the sword, they simply authenticated the inscription. 

[Ray Singer]

I recommend purchasing the ebook below, which will provide you with bios for the Norimitsu who worked during the time period your sword is dated. 

 

https://www.lulu.com...ml?page=1&pageSize=4

[g2nightmare]

Thank you again Ray. I will take a look.