I am also researching the Unkenholz family. Most individuals with that
surname in present-day Lower Saxony seem to be located near Meppen and Lingen. My
own ancestor, Friedrich Wilhelm Unkenholz, came with his family to the US in
1848 from Wilsum, further south, near Nordhorn. I have been unable to find his
birth record. (He was born about 1796.)
Would be glad to help or share information.
Rik Booraem