In an effort to find any additional Koberstein's in the Landsberg area, I searched some of the microfilms available at the LDS Family History Library, December 2, 2005 in Salt Lake City, Utah.

Looked at all records on this microfilm item 1 (which is the Landsberg Catholic recors) scanning Vor und Zuname for Taufen, Heraten, und Tote records.  It took a little reading to get my german script eyes back but I feel I would have picked out any Koberstein names if they were there.  As a matter of note I found a Wendtland and a Hoffman name(s).

Evangelical Military Microfilm 0,172,440.

The readabity was from bad to horrible.  Many surnames were underlined which helped on the scan.  As far as I can tell there are no Koberstein's listed.

Kirchenbuch Evangelical Military (1868-1921), Microfilm #0,172,515.

Readability was God to Jumbled.  I reviewed most of it (about the first 90%) and detected no Koberstein's.

I looked at the book which gives list of Colonists in the Landsberg/Warthe, entitled, "Kolonistenverzeichnisse aus Landsberg/Warthe und Umgebung (1740-1788)", call number 943.15/L2 W2g.  This is a very small book and appears to be a scholarly work to transcribe some old records.  No Koberstein's were found.  The subtitle is (Landsberg/W., Friedrichsstadt, Blockwinkel, Plonitz, Hopfenbruch, Giesenenaue, Dühringshof, und Blumenthal).  This obviously refers to the cities it covers.  Koberstein's are know to have lived in Plonitz, Hopfenbruch, Dühringshof, and Blumenthal.

Sources (Quellen und Literaturhinweise) given for this book are:

Heinrich, G., Runinski, H. u. Scharfe, W., Historischer Handatlas von Brndenburg und Berlin, Lfg. 35, Kolonistenzuzug und Staatssiedlung 1688-1786

Scheer, W.; Ansiedler im Warthebruch im Jahre 1775; in "Der Neumarker", Bd. 3, Landberg/W. 1943

Schulze, B.; Neue Siedlungen in Brandenburg 1500-1800, S. 76 f., Beiband zur Brandenburgischen Siedlungskarte 1500-1800.  Berlin 1939, (= Einzelschr. d. Hist. Kommission f. d. Prov. Brdbg. u. d. Reichshauptstadt Berlin)

Schulze, B.; Brandenburgische Siedlungskarte 1500-1800, Ma(beta)stab 1:350 000, (= Hist. Atlas d. Prov. Brandenburg 2,3)

Beheim-Schwarzbach, M.; Hohenzollernsche Kolonisation, Leipzig 1874

Neuhaus, E.;  Die Fridericianische Kolonisation im Warthe- und Netzebruch Landsbert 1906, (= Schr. d. Vereins f. Gesch. d. Neumark, H. 18)

Kaplick, O.;  Das Warthebruch, Würzburg 1956, Schreckenbach, H. J.;

Bibliographie zur Geschiechte der Mark Brandenburg, T.I-IV