Great poster, but not NSFK. It is Deutsche Luftsport-Verband (DLV). Nationalsozialistisches Fliegerkorps, NSFK, was founded in 1937 as a successor to DLV.
You are right of course Henrik. I had overlooked the start for the thread: NSFK.
The poster mentions DLV and shows its symbol. The uniform worn at right is not
NSFK, but of course DLV!