I agree with Bob. I collect WWII guntos and their tsuba are different than something you are contemplating! You will have a hard time finding a tsuba that perfectly fits your blade, though. Finding one in person will work better than shopping online. Japanese swords vary in size and shape, especially the ones made the traditional way.
Bob, I will quote myself "Sorry, my tablet's auto-correct went wild"! I was in a hurry and didn't proof-read my text.