I am not related unless it is way back but I have been searching the online birth records for Thomigsdorf (Damnikov, CZ) and found the birth record for Johann Rosenzweig. https://familysearch.org/learn/wiki/en/Czech_Republic_Church...
The third paragraph links to a pdf showing online records, Johann Rosenzweig is found in:
inv.c = 1291
sign. = 1091
You click on the link and it will take you to that book
Johann Rosenzweig was born 6 May 1866 to Franz Rosenzweig, son of Johann Rosenzweig and ??? Frodl and Anna Muller, daughter of Ignatz Muller and Anna Frodl
I hope this helps you continue your search.