I have a lot of sketchy information about the Hertz/Hartz line (a lot of names, but not many places or dates). Your Conrad Hertz is my 6G grandfather, he was married to Elizabeth Segnar and had 13 children. Conrad, David and Philip's parents were John Philip Hertz and Susanna Hautz, and they had 3 sisters (Susanna, Juliana and Anna Marie) and a brother, Hans Bernhart. I can probably get more information on the family from my grandmother. Looking forward to hearing from you!