[INM@RLM]

A pleasure. Picqued my interest.

One other point occurs. On this machine the fuselage Trennlinie for the upper surface colours is very high; just a narrow strip of darker shades down the spine of the aircraft.
In this same period other I./JG 1 aircraft have a noticeably lower Trennlinie that starts from the level of the bottom ledge of the cockpit canopy. Both finishes are evident in photos of the unit's aircraft during their brief sojourn at Charleville, with the majority of those seen having the higher dividing line. (See PSRB Teil 3 pp.78/80.)
Others will have studied this more closely, but the higher Trennlinie seems to have been superseded by the lower version (e.g WNr. 1559, Teil 3 pp.78/80) with that in turn being replaced by a division midway between the two earlier forms, when mottling of the fuselage sides was added at the manufacturer (e.g. WNr. 1609 dated in Aug-40 at Carquebut, Teil 4/I, p.412 top). On the surviving evidence then the high Trennlinie on this aircraft is more suggestive of a May date than one in August.

This photo is as much to do with Brittany as the three photos of a Go 145 hanging down the side of a building in Orléans. (Search the Musée site for Avion Allemands.) These have simply been rescued from photo albums, and the scribbles along the bottom border here are clearly remnants of the owner's handwritten captions in his album.