Hello,
Currently on ebay is a line up of Junkers J.I. Nearest the camera J.857/17 and next back J.815/17 I think at:
https://www.ebay.de/itm/Foto-Feldflu...QAAOSweFhevTkL
J.857/17 is known to have served with FA (A) 263, so perhaps that is the unit depicted.
I'd also welcome other views on whether I've read the serials correctly, since upon checking I've already seen this photo which was either captioned J.867/17 and J.818/17 or that's how I read it at the time.
Regards,
Clint