Moss coolers are exceptionally rare as Coke chose utilize the Glascock cooler in the 1920's.
They made 2 sizes this is the smaller sized size ... ... 2 cases.
Exactly what does not appear to be initial is the bottom horizontal braces and the tank is copper
I have no idea but I can only presume the tank would of been galvanized then. There is no info out there on these. I have actually discovered a copy of the initial advertisement on a Collectors vending equipment website.
They even state "they were lucky enough to have possessed one".
I would safely state you will certainly never see another one.