Spanish American War US Pattern 1878 Canteen

Description

This has all the looks of a Spanish American War US Pattern 1878 Canteen, but not certain and no guarantees. The side loops would hold a 1/2" sling, they used to swivel but are rusted tight now. The cork stopper is intact, but appears frail, I didn't pull it out, but it does move up and down a bit.
In as-found condition, I didn't wire-brush it, rub it, or make any attempt at cleaning it at all. Even in bright sunlight, I can't see any marks or embossing. The back is dished in on purpose.
Bottom to top of cork ring; 9 3/8"
7 3/8" diameter
25/8" thick