I have tried via Google search to figure out what this is but I keep getting a sextant, or other items I know it is not.  If you know please let me know.

It is rusty obviously but not bad at all.  I cleaned it a bit but no steel wool or any abrasives.  Just knocked the spider webs and gunk off.  From a barn sale near me, no one knew anything about it.  The handles rotates in a circle and has a cutting point as you can see from the scratching in the bottom plate.  It slides from left to right also.

There are lots of photos and no names or numbers on the item.