I agree it is some sort of a plunger pump,but who knows what from.It looks like the barest hint of a thread in the inside cap,like it would thread over a barrel,or tube.It could have been for oil,fuel,air,with that wooden handle it could have been to pump up kegs of beer or to prime up a cookstove.The wooden handle could be original or could have been added to make something pretty.Look on the sides of the old race cars and you will see the oil pressure pumps the riding mechanics had to keep pumped up.If you searched out that name you may find a picture of some antique with that handle on it.It is still a neat thing to hang up,I have dozens of things like that.With all the people that run through my place there is always somebody that spots some trinket and knows what it is.