Its a big brass pin punch. It was for hammering something out of something kind of fragile, that you didn't want to mark up.
Either that, or a gunpowder/gas/gasoline/propane plant where you couldn't afford any stray accidental sparks, or the whole place could go bloooey!
You can see it has been used a whole lot. That "mushroom" of metal on the top? Where it widens out??
That comes from hammering and hammering.
The fact that the little end is still smooth means it was dressed down after every few uses, or it would be all swelled up too.
yours Scott
