This isn't much but is what I have;
Nachtaufklärungsstaffel 3
Unit Code K7+
also as: Nachtflugstaffel 3 (Jun 41 - Apr 42)
Nachtaufkl.St. 3 d.Gen.d.Lw.b.Ob.d.H. (Apr 42 - c. Nov 42)
3.(F)/Nacht (short form in use 1942-45)
FpN: L 31545.
http://www.ww2.dk/air/recon/nst3.html
Peter