Gentlemen,
Thank you for your comments. I still feel like winning the lottery here, since I wasn't expecting to have a real nihonto. The fact that it probably is "just" an unsigned wartime gendaito doesn't cast a shadow on my joy. In fact, I would feel a bit guilty for accepting a casual gift that turned out to be much more valuable than the previous owner thought.
How about having a just a foundation polish on this one? That way, I could restore it back to its functional beauty. In the spirit of the time, it was never intended to be an art sword, but a weapon first and a badge of office second.
Of course, even a foundation polish would set me back a bit, but it just makes me sad to see a well-made weapon in a non-functional state.
As far as I understand, it's not valuable enough to warrant a full polish, yet too valuable for amateur polishing attempts. In the firearms collecting world, I have seen too many nice historical guns ruined by well-meaning amateur "restoration".
Anyway, this sword will be the gem of my modest collection.
Cheers,
Ossi