Hello ,
Currently on ebay is a photo of a machine with either Russian or Bulgarian military personnel at:
https://www.ebay.de/itm/Flugzeugbild...QAAOSwSdFfp~ew
I assume it is either:
a] An early Farman - Farman VII perhaps?
b] A copy of a Farman design built by Dux?
c] None of the above?
Regards,
Clint