John R.
My Holtz family lived in Kambs bei Roebel [should have umlaut over the "o".]
Kambs is in Mecklenburg just east and a little south of Lake Muritz which I am sure you can find on a map. At one time they may have lived in Sietow which is just north of Roebel. The towns or villages must have been very small as it is difficult to find information on them.
Rita Hartwig.
I have one ancestor with a middle name of Hartwig. Johann Hartwig Christian Holtz. Since it was common to name a child after someone I wonder if you might have a connection? Just a long chance.
Phyllis Holtz Smith