I started collecting antique Japanese swords not long ago, and this is my first post here. If it is in the wrong place, please let me know.
I'm brought to understand that the fit between blade, habaki, and saya needs to be exact, yet I noticed almost at once is that there are many koshirae, complete, for sale with no blade and there are many blades with no koshirae in a holding scabbard.
How did they get separated? I'd imagine they can never be reunited due to the exactness of the fit required, but is that wrong? Is there a secret I'm unaware of whereby one can purchase a blade in shirasaya and not have a koshirae made but bought off the rack like a pair of pants? (I imagine that's silly, but I still wanted to ask.)
And I ask because some koshirae are absolutely magnificent just by themselves, even the unreplaceable parts. It would feel bad for those really fine ones with unrecoverable art to be broken down for parts to be matched to a blade... but also sad for them never to be matched to a blade again.... which raises the question how so many swords ended up without their koshirae?
Surely most of these shirasaya blades at one time had one or many koshirae... and if they are the only ones those fit... were are they? Why weren't they kept together? Tt would seem that a sword should always be sold with every set of Koshirae that has been made for it, yet it is clear this very rarely happens.
(That said, I did have the idea of using cat scans or xrays to map the koshirae and 3d scanners to figure out how many might be made to match, but I know how difficult that would be logistically.... even if theoretically possible.)
So my questions are "IS there a secret I'm unaware of to buying a koshirae and somehow matching it to a blade beyond just using it for parts?" and "How did so many get separated instead of kept together, especially in a culture so very good as taking care of their antiques?"
Thank you all in advance for helping with my ignorance on this matter.