Duchateau & Brother Green Bay - pint

Aqua pint strap sided flask embossed "DUCHATEAU & BROTHER GREEN BAY WHOLESALE LIQUORS" in a slug plate. Has an applied lip and smooth base. Bottom is embossed "PAT'D AUG 6TH 1872 H. FRANK". Dates from the 1870's and is extremely rare. Aqua is an unusual color for a strap sided flask of this age. Wisconsin whiskey bottlers seemed to favor amber flasks.