This is the Case V-42 Military Commemorative Knife [more info on Case's website here]. It is based on the V-42 stiletto used in World War II.
I love this dagger. It's one of those knives which surprise by how light and nimble it is. The edge geometry, the symmetry, and overall stabbiness is top-notch. If this knife doesn't sell, I'm not going to weep.
It is unused and isn't modified by me. It comes with the sheath that they sent it in. I don't have the original box, but who cares.
Marked on one side is "V-42 USA 2015"