Hello Kees,
One more piece of the puzzle.
Jezierzyce Słupskie formerly
Jeseritz is not exactly the same place as
Seddin although very close. I think this is it. Precise location of
Jeseritz is 54° 30' N and 17° 07' E. Here is a map.
Luftschiffhallen had to be somewhere in the area.
Here is a quite good picture of two
Luftschiffhallen in Seddin, one of which was dismantled.
Greetings
Marek