Tanto: What do we have here?

[Rich]

Yes, quite common for blades (of all eras) to be unsigned. About half of my
collection is composed of mumei (unsigned) blades. It may (?) by possible
if the blade was in better condition to make a guess as to the school or
even the smith. But again that requires someone much more knowledgeable
than I; in hand inspection and the blade in good polish.

There were a variety of reasons why blades were unsigned. For some smiths
it was considered improper to sign them; for others they didn't sign because
they felt it wasn't their better work; many blades have been shortened over
the years and the signatures cut off.

Rich S