[78-L] Dating some Grammophon records

[Harold Aherne]

Can anyone provide the approximate months of recording for the following Grammophon
discs? They all carry a mechanical copyright notice of 1929.
 
Gr 22033 (Paul Godwin)
Hallo, Margot (Katalog Nr. 50767, matrix? 74-BT-III)
Fräulein, pardon (Katalog Nr. 50768, matrix? 76-BT-III)
 
Gr 22203 (Paul Godwin)
Wenn der weiße Flieder wieder blüht (Katalog Nr. 50937, matrix? 1813-1/2-BR-II)
Vier Worte möcht' ich dir jetzt sagen (Katalog Nr. 50938, matrix? 1815-BR-II)
 
Gr 22258 (Harry Jackson)
Hochzeit der Holzpuppen (Katalog Nr. 51011)
Das ist die Broadway Melody (Katalog Nr. 51012)
 
The Katalog numbers, if I recall correctly, correspond to the "single-face" numbers that
DG's separated cousin the Gramophone Co. continued to use even after they began 
pressing double-faced discs and as such, they may be of no real discographical significance, but I included them anyway. Only the Katalog numbers were visible on 
22258.
 
-HA