These early, post-war, East German canteens are a nearly identical match to the late-war (WW2) M-31, German army canteens. The only real difference is the type of leather used on the straps and the metal belt clip is a slightly different style. These East German models were issued to the Barracks Police (pre-army forces) and later the Army, from the mid 1940's to the mid 1950's, the exact time period that my BGS bike dates to. The early BGS canteens were nearly identical to both the WW2 and East German canteens.......... a near perfect match!
The canteen itself has no markings other than "TPW", or it could be "Md1", dependening on which way is right-side-up, on the cap and cup. No dates. Based on this, I would date this canteen to the 1940's, before the East Germans adopted a standard date-ID system. The WW2 German canteens have a three letter stamping on the cup and canteen necks (bot matching and in capital letters as well). According to my internet research , the three letters represent the manufacturer (found on all WW2 canteens as well). My guess is that one of the factories that made canteens during WW2 found itself in the new East Germany and just kept stamping out canteens for the new German Police and Army, using the old dies and patterns. In the late 1950's, the East German Army switched to plastic canteens with a flat bottom, in a cheap cloth cover, and tapered metal cup.
I am still waiting for a back-ordered batch of old Swiss Army surplus bread bags (from my super-secret source !!!!) that I will use for "saddle bags" on the back of the BGS bike. The shovel, canteen and mess kit will strap on the outside of the bread bags.