Naginata Koshirae

[Rye]

I have recently purchased an antique Naginata Naoshi, though the shirasaya it came in is quite loose. I've studied saya making for about a year now. I've made tsuka and saya for plenty of tanto, and a couple full length Katana, but I've never worked with a Naginata before, though it's my favorite weapon. I'm looking to make a shorter shaft for the Naginata, as well as replace the habaki (it has a nasty crack on the back) and fit it with new koshirae. I'm not sure what the name for Naginata fittings are, and I've had no luck finding them for sale anywhere. 
The tang is about 10 inches long with a 14 inch long blade, and I'm unsure of how long to make the handle, as I don't want to damage the blade.

And I'm wondering if anyone has any recourses about making Naginata saya. 

I also plan on making a shirasaya for it. 

[Franco]

What a good reason to attend a sword show in search for answers, where almost assuredly (???) there will be trained artisans in attendance. Brian Tschernega and John Tirado are two to consult with, try contacting. 

[WillFalstaff]

“Japanese Spears: Polearms and Their Use in Old Japan” by Patricia Knutsen and Ronald Knutsen might be a book that can help you. It’s pretty expensive, but from what I’ve seen it’s the definitive book about polearms. 

 

https://www.amazon.com/Japanese-Spears-Polearms-Their-Japan/dp/1901903567