Tanto: What do we have here?

[Rich]

Can't tell a whole lot about the blade due to lack of pics of it. I suspect
Late Shinshinto. The horimono (blade carving) is poorly done, so I suspect
a later addition perhaps to cover a flaw in the blade (commonly done). The
koshirae are most likely post war pieced together (nothing matches) done
for sale to the West. Keep in mind this is all speculation based on pictures
and I could be very wrong. Still could be an interesting coffee table tanto -
nothing wrong with that, I have a couple of them :-) However, I would
strongly recommend it be seen in person by someone knowledgeable in
Nihonto before you or friend think of having it professionally polished. The
polish could cost more than the tanto is worth.

Rich S