This was not an easy project, and I had limited success. I found the civil birth of Clemens Zirotzki, born 13. February 1878 in Zuckau, son of Johannes Zirotzki, Arbeiter and Auguste Bosch. There was a note which stated that he changed his name to Zerold in Danzig on 31. October 1940.
I then looked for the marriage of his parents in the civil and Catholic church registers, but did not find them listed. I thought Clemens' church christening might provide further clues, and found that it was very different. His parents were now given as Joannes SIEROCKI and Augusta Bosch, and his date of birth was 19. February. With that new spelling of the surname, I found his parents' marriage. Johann Sierocki (age 27, unmarried, and a resident of Zukau) married 22. October 1871 to Augustina Bosz (age 23, un- married, and also a resident here). Unfortunately, their parents' names were not provided.
With their ages known, I tried to find their christenings, I checked 1842-49, but did not find either one. I did see these surnames, however, but not children with those given names. I once again looked for their deaths in the Catholic registers, but still did not identify them.