Austro-Hungarian-German Leather Glass Canteen Help Identify

[canteenmanUSA]

Hello, I need help to more definitely identify these leather covered glass bottles I have gathered that I believe to be German or Austro-Hungarian bottles from between 1865 and 1912(Date stamps I have seen) The only country identifier I have ever seen on one is a "Portugal" stamp on the aluminum cup covering the bottom of one.I have seen these for twenty years.Obviously they were made for 50 years but for who exactly. Were they just private purchase for home reserves and occassional use, annual reserve training?Did .Portugal make them in total or just the metal cup I found on one?