I've never seen a bottle like that. Kind of shaped like canteen's from 150 yrs. ago but don't think it's big enough for that. Hope you get an I.D., it's pretty cool. Good luck.
The bottles are very cool. The oblong one is generally called a torpedo bottle. I would let them soak in plain water with a touch of Dawn in it, to loosen some of that dirt..., Usually they have longer necks on them, though. Usually they had cork's in them. I'm curious as to why they have, what looks like metal bands on them. They had soda or mineral water in them. If the corks dried out the CO2 would escape from the drink, so they stored them on their sides, much like wine bottles of today. Since they were meant to be stored on their sides, there was no reason for a flat bottom bottle... Here's a sample of the torpedo bottles..... https://www.google.com/search?q=tor...A3ZfcAhVs4IMKHTtSBU0Q_AUICygC&biw=983&bih=707
It's garbage, mail it to me and I'll take care of it for you! Hahaha, nice bottle though must be a wierd round bottom flask. I have around bottom old wine, it's the one laying down in the middle.
I'm pretty sure what you have there is a glass toilet bowl float.
So no need for a flat bottom.
They are pretty rear and that one is very cool.
Two other ideas are wall soap dispenser or a float for a livestock watering trough.
All of my searches come up with the same images, so no exact matches.
Bing image civil war canteens, you won't find but a few that aren't round. You cant sat something round down, they had to stay in a case of leather and strapped around something, if not, then private Joe Snuffy forgets he set his canteen down and marches on down the road with nothing to drink
Alright, I tried to reply to certain posts but they all ended up at the... It's pretty easy to figure what goes to what. And thanks everyone for your input.