This is an original fuel mixer or carburetor for a small Nelson Brothers hit and miss gas engine.  It is part number P-4 and is in excellent condition with no cracks, breaks, or repairs except for a new choke plate which was nicely done and effective.  It fits into a 1 3/16" hole in the bottom of the head and is from a 1 1/2 or 2hp engine.  The fuel needle moves as it should and is in great shape.  This was on a running engine when removed from service.  These original parts are quite tough to find in the wild or even at swap meets!  If you've been looking for one to complete a restoration here's your chance.  The pictures tell the story.  It would surely beat making one!  I can be reached at 262 573 193 1 if you'd like to talk about it.  Good Luck.