Franck, I acquired his image in front of the E-4 (propeller with green spinner). Seems that the late Fw. Helmut Kabas was probably serving with an Erganzungstaffel at Cazaux, between November 1940 and March 1941; probably Erg.St./JG 54, according to De Zeng (
https://www.ww2.dk/Airfields%20-%20France.pdf)
There were several images of some Bf 109 C and E from the same seller, including one showing a Bf 109 G-6 with the 7./JG 54 emblem visible, selling.
Adriano