“German” Factories in the Czech and Slovak areas under German Control did not suffer the damage that plants in Germany Proper suffered from air-raids, etc. Even at war’s end, relatively few Czech towns and factories suffered any damage unless it was from Waffen-SS demolition squads, usually not very efficient or timely; actual “Battle” damage from Soviet/Hungarian/Bulgarian artillery was only sporadic.
The Powder could have been stockpiled at PS or elsewhere in either Bohmen-Mahren ( Czech side) or Slovakia from during the war; and the PapierWahren was based in the Sudeten Gau ( district) which was part of Czechoslovakia before 1938 and then immmediately after May 1945 again. So stocks of cartons were stored there as well.
The Czechs continued using German Code indicators during 1946 and even up to 48, as well as using Componentry held in stock or “work in progress” from before May 1945.
Interesting times in the former occupied Nations and satellite nations of the Reich.