Now that the LDS has posted German records to FamilySearch, you may want to take a look. I found a Jacob Zeuch at Niederdunzebach (don'tput in the "e" for the umlaut) christened in 1750 -- which pretty much agrees with the information in HETRINA. Could this be our Jacob? I think so. Furthermore, I believe you can work him back a geneation or two from there . . . or at least get enough information to see if you can find which church (likely Lutheran).There may even be enough to identify brothers and sisters. I'm not going to spill all the beans and spill all the fun of discovery! Let me know what you think about this.