This is not my area of expertise, so take this for what it's worth...
The unoverprinted versions of these stamps were joint issues of the Allied Control Commission which initially governed occupied Germany. On 21 June 1948, the Soviet Military Administration broke with the western Allies and instituted its own monetary reform in East Germany. With this monetary reform, it became necessary to have new postage.
Soviet produced stamps were not issued until July 3. In the interim, the Soviets authorized use of the remaining stocks of Allied Control Commission pfennig valued stamps at 1/10th of face value. Each post office was required to overprint the stamps with a distinct stamp. The overprinted stamps were valid until 31 July 1948. Because the cancels were done with local cancellers distinct to each post office, there are thousands of distinctly different varieties. Michel notes that a vast, vast majority on the market are forgeries, and BPP expertization is required to get the used catalog price.
The overprints consist of a district number and the post office name. There were 10 districts (Bezirk) -- 3, 14, 16, 20, 27, 29, 36, 37, 38, 41.
There is (as far as I know) no existing list of all the post office in each district that would allow you to match the post office names. Michel does, however, give a list of the most commonly forged post offices, which might allow you to narrow down the geographic area of Bezirk 27 and 36.
Most commonly forged post offices:
Bezirk 3 -- Berlin 4, 7, 8, 9, 17, 25, 34, 54, 55, 56, 66, 92, 113, 115, Berlln-Baumachulenweg, -Buchholz, -Karow, -Kaulsdorf, -Lichtenberg, -Mahlsdorf, Weißensee Bezirk 14 -- Dresden 1, 6, A 19, 20, 26, 28, A 39, A 53, Bautzen, Bischofswerda, Elbau, Freiberg, Graupa, Großenhain, Görlitz, Herrnhut, Löbau, Meißen, Niederoderwitz, Pirna-Copitz, Riesa, Schirgiswalde, Zittau Bezirk 16 -- Altenburg, Apolda, Arnstadt, Ellrich, Erfurt, Gera, Greußen, Ilmenau, Jena, Katzhütte, Meiningen, Meuselwitz, Oelze, Orlamünde, Saalfeld, Schleusingen, Schweina, Sonneberg, Steinbach, Bad Sulza, Tanna. Bezirk 20 -- Bitterfeld, Calbe (Saale), Dessau, Halberstadt, Halle, Harzgerode, Heringen, Hettstedt, Bad Lieberwerda, Magdeburg, Osterwieck, Pretzsch, Rosslau, Staßfurt, Wegeleben, Weißenfels, Wolfen, Wittenberg, Zeitz Bezirk 27 -- Leipzig S 3, 9, 12, 18, 22, 23, 24, 25, N 26, W 35, 37, 40, Chemnitz 8, 14, 19, 21, Aue Burgstädt, Borna, Engelsdorf, Gaschwitz, Glösa, Hainichen, Hohnstädt, Markkleeberg, Miltitz, Pegau, Taucha, Wurzen Bezirk 29/2° -- Schönebeck 1, Thale, Köthen, Quedlinburg, Raguhn Bezirk 36 -- Altenhof, Birkenwerder, Brandenburg 3, Caputh, Cottbus, Eichwalde, Finsterwalde, Forst, Grube Ilse, Jüterbog, Luckenwalde, Michendorf, Oranienburg, Potsdam, Potsdam-Babelsburg, Rehfelde, Bad Saarow, Senftenberg, Spremberg, Wildau, Wittenberge 1 Bezirk 37 -- Bützow, Crivitz, Bad Doberan, Fürstenberg, Güstrow, Lübz, Schwerin, Sellin Bezirk 38 -- Anklam, Greifswald, Pasewalk, Saßnitz Bezirk 41 -- Chemnitz 1 u. 4, Crossen, Bad Elster, Erlbach, Gelenau, Glauchau, Netzschkau, Niederwiesa, Ölsnitz i. V., Plauen, Reichenbach, Schwarzenberg, Treuen, Zwickau |