Persons asked for the passport, district (county) authorities, usually.
District was named "Bezirk" in German, "okres" in Czech.
If the passport request survived until today, ones had to be stored in District Archives (okresni archiv).
But my personal experience is that passport requests for the most districts are missed.
Nevertheless, you can try contact the Distrrict Archive(s).
As i understand you are interesting in Prachatice area, correct?
District Archive of Prachatice:https://www.ceskearchivy.cz/en/sdas/sda-prachatice/study-roo...