Usagi Yojimbo DojoBoard

Something I've heard only rumors about for several years now is that there are supposed to be organizations in both Japan and America that seek out artifact-quality katanas taken as prizes of war back in WW2 and return them to the families of their original owners in Japan. Does anyone here know anything about where to find out more information about these groups and how they go about their business?

It's something I'd love to work into some writing of mine in the future when I get more information about it.

Thanks for any help.