Bruce, an interesting post.
I know nothing about Japanese swords, but a quick look on Giggle tells me that Japanese families had their own swords. If they never wanted to take their family swords to war, the government would issue them one.
So, there are possibly two sorts of owner;
1. the Japanese military,
or,
2. a particular family.
You would need someone to sort out what this sword is, and then decide if it goes back to;
A. the Japanese army (military??) or
B, a particular family.
I'm guessing your sword has a reasonable collector value? It has a history.
If it belonged to the Japanese military, I'm sure they have a few already.
If it goes to a family, would they, or a particular person appreciate the return of it.
What would they do with it???
Why not a collector?
Are you on this forum because you collect something?
As bad as collectors may seem, they are the people who appreciate these things, otherwise we would be playing golf (apologies Rob)
It would be interesting to hear your reasons for why you don't believe in moving it on to a collector.
The reason for my interest in WWII militaria is the technology of the day. I have never held a Japanese sword, but I'm sure I would be facinated by it, if i had it in my hands.
Some good photos would be nice to see.
If you cannot find a home for it you could entrust it to me!
, and I could tell people the story of how I came by it! (I know that's not going to happen!)
Lastly, don't put too much faith in private museums.
It would be quite a story if it had its origins with an old Japanese family, and was returned to the family. The stuff of documentaries.
Keep us posted.