Orphan Johannes Opp (age 11) is recorded on the 1767 census of Brabander in Household No. 43 along with the Peter Müllecker family. The 1767 census does not record a relationship between the Opp and Müllecker families.
The 1767 census does not record from where Johannes Opp came.
- Pleve, Igor. Einwanderung in das Wolgagebiet, 1764-1767 Band 1 (Göttingen: Göttinger Arbeitskreis, 1999): 224.