I got this at an antique shop last week on a vacation trip to the Rockies. I don't know horns, but it's flat base plug I think it New England? No sign it every had a strap loop on it.
It has an unusual repair in the side that is plugged with pewter or lead, it's non-magnetic. The nails are square.
Does the spout look complete? Or was there a piece on it, now lost?