Is this a real Japanese Naval Dirk

[CT7212]

My grandfather had this dagger for many years and passed it along to me. I've done some looking around the web but have no idea if it's real or not or what version it is. Hoping I could get some assistance here.

The blade is about 8 3/4 inches to the tip from the cross guard.

[ghp95134]

The harp-looking logo on the guard is the Tokyo Suya logo; The "harp" is an artistic version of the first kanji in their name: 壽

壽屋商店
Suya Shōten

See JapanX's informative site here.

-- Guy

[Bruce Pennington]

For an in-depth article on Suya Shoten, see Nick's piece here: Ｔhe Untold Story of Suya Shoten

Ohmua's site has some history of the dirk, with examples of several versions here: Naval-Dirks