Hi Tobias
The book
Bloody April..Black September is really good for your question.
But they does not seemed to publish the official German scores for this month as follows:
The German claimed 362 e/a and 29 Ballons this month. Of the e/a fell 12 on other fronts and no ballons.
291 e/a were claimed in air combat on the West Front and 8 on other fronts.
German Flak units claimed 48 e/a on the West Front and 4 on other fronts. Of the Flak claims on the West Front fell 28 within German Lines and 20 over enemy lines. 4 more e/a were claimed by Flak units as Forced down over enemy lines(These were not officialy confirmed).
11 e/a were claimed as Forced landings within German lines, all on West Front.
Of the total e/a fell 171 within German lines. 169 of these on West Front and 2 on other Fronts.
This 299 + 52 + 11 = Total = 362
The German also sometimes had victories which were reconfirmed. And perhaps a few victories should be added to these but its difficult to make any correction with the material we have today. But Frank Olynyk seems to have recieved this kind of material newly from Germany...
VBR
Gunnar