Thank so much for your reply. We have DNA results for Jacob and several other French males who match Jacob but were born later than Jacob. It would be very interesting to see the DNA results for Ludwig Frantz. Have you checked with the administrator of the study to see if the price has gone down or if there a Frantz fund that might help pay for the test?
Jacob French is only a 2-3 genetic distance from the Hamman Frantz (or William Otto Frantz) listed on the Frantz DNA study. This Frantz group has a haplogroup of G and does not match the other Frantz males listed in the project (http://www.familytreedna.com/public/frantz/default.aspx?section=yresults).
Simon Earsom / Ehrsam / Ersame (an in-law of Jacob French) was a member of the Emmanuel Lutheran church in Lancaster County, PA. The list of church members that I found for this church also includes "Ulerich Frantz". Is this Ludwig or someone related?