Frank,
I don't know if this will be any help or not. Many Oldenburg families settled in Hooper, in Dodge County, Nebraska, where they founded St. Paul's Lutheran Church. I understand that a copy of the churchbook is available in the Staatsarchiv, though I do not have the details. For more information you might telephone OGF member Manfred Moenning, 56 Parkstrasse, in Hude. I know he also has a map of the area showing the names of families living there.
Hugo Schroeder
Liverpool, PA