Not a dagger but a bayonet story:
I asked an older woman if she had anything military wise she'd sell. She told me she had a bayonet and went back into her house to retrieve it. A few minutes later she came back out dragging something behind her. Oh she had a bayonet alright. What she had neglected to tell me initially was it was mounted on a Dutch Beaumont rifle!

Now for a dagger story:
I bought a dagger from someone who made the usual claim of "taking it off a dead German". This "German" must have been in multiple branches of the military as it had a Luftwaffe pommel, a Navy grip and the shortened(Army?) blade was housed in an Army dagger scabbard! I wish I had taken pictures before I sold if off to a fellow collector for parts.
Jim