The Bartholomai family (settlers in Frank and Walter) can be traced back to Hans Bartholmess who died in Wüstensachsen 1690. Hans' son Heinrich was recorded as having been from Wüstensachsen also, and was married to Eva Richter in Gersfeld in 1690.
Five Bartholomai families (descendants of Heinrich and Eva) arrived in Oranienbaum on 14 September 1766. The Walter First Settlers List includes Nicolaus Bartholomai and his wife Dorothea in Household #17, and Georg Elias Bartholomai and his wife Elisabeth Schoessler in Household #103.
George Elias' son Adam Georg moved to Frank before 1811.
Parish records of Gersfeld on Archion.de
Pleve, Igor Lists of Colonists to Russia in 1766: Reports by Ivan Kulberg: pp. 406, 407, 409.
Pleve, Igor. Einwanderung in das Wolgagebiet, 1764-1767 Band 4 (Göttingen: Göttinger Arbeitskreis, 2008): 299, 318.
Pleve, Igor. Bartholoma Family Chart.