Hello,
Currently on ebay is a photo of a DFW Mars biplane with the Nnumber N 59 at:
https://www.ebay.de/itm/FOTO-FLUGZEU...4AAOSwZbJe2RNd
This photo is fairly well known though the quality is better than usual.
The N 59 marking is noteworthy. Is it a serial of a civilian operated flying school. Are any other early war German aircraft known with this sytyle of N.** marking?
Regards,
Clint