This other bit from SunDeck's comment jumped out at me:
The other side of the family is well documented by a relative. I email with my cousins in Riemsloh occasionally- they live on the dairy farm that has been in the family since 1100. Interestingly, they seem just as interested in the family history as we are. There were three out of four men who left for the states in the 1870s (the farm passed to the eldest) and it was a complete mystery to them what had happened to them.
This is how I broke thru the wall on my Germann side, a 2003 note on a genealogy board from a volunteer at a German town's historical society looking for descendents of some folks who left their village. My great-great grandfather's name jumped out at me and I located the woman who sent it. She sent me what she had and I've since confirmed it is my family. We changed the name from Görmann upon arriving in the U.S. Basically the village decided they would try to track down what became of these folks. Glad they did.