Just saw this, though late. Maybe the info will help others in passing. The German Bush chickens or Javanese Bantams aren't very common to my knowledge. I know very little about them, but I want to say they originated out of Jungle fowl (or Old English?) and just local landraces (which could be anything). There was a German forum I was on, which I think was gefluegelforum.eu. We do not have them in the US and as Mice said, not very common in Germany.
There is a very kind lady on the forum provided called Claudia that to my knowledge all she keeps is Deutsches Buschhuhn or in English, German Bush Chicken. She speaks English relatively well too, so you shouldn't have to worry too much about not being able to understand each other (or maybe you speak German?).
When I was looking for information on Kraienköppe she supplied me with the German standard (as at that time I hadn't bought the book on them and only had the Dutch standard) and helped me with translations on some information I could not easily translate myself; she also helped me with some German poultry terms I could not really understand being American as they are not terms we use here.
German's have some cool birds, I think next to the Kraienköppe Ramelsloher's are my favorite.
