Nihonto Club

Jihada: There is a tobiyaki on the shinogi line. Muneyaki can also be seen all along the mune.
Nakago: Shape and condition of nakago could suggest that it's o-suriage, shortened from katana or wakizashi.
Hamon: Mainly ko-midare in thick nie deki with gunome midare in monouchi. Few nie sake can be seen, as well as kuichigaiba closer to yokote.

This is a Jumyō wakizashi or katana, shortened to a tanto size in mid-late Edo. It could be one of those 'boy swords', especially looking at the way it's been mounted.