Vintage Antique copper Fire Extinguisher not empty with wall hanger

Description

I think this is copper, but maybe it's brass . .
The copper is turning green & i didn't want to clean it off; maybe it's nicer with the green aging.
It's about 16 inches tall and the only marking s on it are on the pressure gauge which says USG u.s.gauge 15176-1
It's heavy - 4lbs 7 ounces
Will ship to Canada or USA or ask . .