I collect as well as resell powder flasks & horns. There are some exotics but seldom run into any that would be considered as antiques. You really have to pay attention to the valving and spout areas. In additon, I also make my own horns and pan chargers. Can you tell us what you see as some are pistol flasks and others are rifle shotgun flasks. .....
Again, if you like the look of it, buy it !! .....
Be Safe !!!