I don't know how much help we can be be here is just a little bit about our Behrndt family, of which we are a part. My GGgrandfather was Johann Behrndt who was born in Preddohl, Prussia in 1812, He immigranted to the US in 1869 with his wife and four children and settled in Marion County Il. His children were born in nearby Falkenhagen, Germany which is in Pregnitz county, near Pritzwalk. The town is about 40 or 50 miles NW of Berlin. We visited the area in May of this year. We think that his brother came over also and settled in Chicago with extended family moving to Wisconsin.
We orginally thought the odd spelling of the name was a mistake taken from Behrendt which is fairly common, but the name without the last e existed for many years.
I don't know what info you are looking for but if we can help, contact us. Roger Widdows