That reminds me of a flask a guy used at many Rendezvous back in the seventies and eighties. It was copper and fluted from the bottom right up to the spout. It had old brass cup hooks bent to make them a closed loop, on the sides, and a small brass drawer pull soldered to the bottom. The nicely fluted copper body of the flask was a recycled toilet float. He must have either seen one like this one, or made them both.
Hungry Horse