Any ideas?

[Deepseeker]

Well done Manpa too! :trophy:

 

[HarryHoudini]

Gun powder shot measurer for blowing stuff up. being brass was a good clue. Brass equals no accidental sparks bottom right of bottom pic is closest. First pic is a more primitive version. EDIT : Thanks every one but Manpa got it before I did :awful:

That is exactly what it is, had me stumped.
But looks exactly the same.

Cheers and thanks to the brains trust

 

[Nightjar]

Great find, HH, definitely a treasure.

 

[HarryHoudini]

Could it be a vintage bottle, flask or gunpowder stopper with the lever acting as a wedge to hold it in place, squeeze the lever to release the stopper?

Spot on cheers. You guys have so much knowledge, and you are happy to share. cheers hh