looks like Brennabor's lightweight motorbikes of the 30ies all had the clip-on Sachs engine and pedals:
http://www.brennabor-brb.de/start.htm (click on Produkte->Motorrader->Motorfahrrader)
Maybe there were export options with footrests and other engines?
The forks look quite similar to yours and the front of the frame as well but the seat post angle is different.
Cheers
Andy
