Stuka pilot tropical uniform identification
 

Any information concerning the uniforms of these Stuka pilots and their unit welcome. These photos were taken before 24 Sep 1943, the day when the Pilot (see photo Alex Uniform Zagreb) was MIA. On the back of the photos there is a blurred stamp with only 'ZAGREB' legible, unfortunately no year recorded. Why were they equipped with tropical uniforms? Presumably these pilots were stationed in Zagreb / Agram as part of Schlachtgeschwader 2 / StG 151 (?). For sure one of the Staffelkapitäne around 24 Sep 1943 was Oberlt Suchtrunk.
(see also post Luftwaffe and Axis Air Forces / Uffz Alexander Ochs II / StG 151 MIA 24.9.1943 from 10 June 2013 with information from aircrewrembered.com)
Thanks
Tilman