Some kind of nail puller???

Sorry the pictures loaded upside down... why I don't know. Anyway, I found this little tool in the bottom of a box of vintage hardware that I bought at an estate sale. It says "Victory" on the back side. It appears to be some kind of nail puller, that would extract the nail as the thumb screw is tightened... Is it for a picture frame? The part with the thumb screw looks like it would need to clamp on to something... Help me out, what is it? Thanks...