i have thought about the powder theory,, let me ask, does anyone know if that when powder was in small kegs, did they have a spout? This could have gone over it to measure powder, look at it, firt pic, brass is stretched from going over something...
I was thinking the salt dispenser, but trench art is very interesting. I also thought something to measure spices and such for cooking. i really like the trench art thing. i really think this went with something else.
With all the notches and numbers it looks like might have been some sort of dispenser and it's missing a bottom piece . That might have had chambers that held something so when you put it on a number and tipped it the contents ( whatever it was holding ) came out thru the hole on top .... just a guess . Woodstock
I'm going in an entirely different direction, and think it's some type of vintage release valve perhaps for steam or water that when dialed to the higher number allows a larger openings.