Stumped is the word.
About all I could tell you is that the bottle appears to be earlier 20th century.
It kinda/sorta feels like the glass thickness is intentional, but why have a thick base and thickness on two edges but not on the front and rear?
Also, when you say the stain is coming off, what exactly do you mean? The color of glass is inherent to the glass and is not water soluble. I have heard of people who spray lacquer over a bottle to change the appearance but such a film will separate easily with some warm water.