This is a refillable flacon of Opium.
I got it from the internetz, as an empty bottle, and I got some Guerlain in the bee bottle from the same seller who poured the Eau du Coq into the Opium bottle. Which is not important as such, I'm telling it only to demonstrate that there should be a way how to open the case of indefinable gilded metal.
Yesterday I was poking the thing, pulling and screwing here and there and I didn't find a way how to get inside.
Now, dear readers, do you by chance know?