Messerschmitt Bf 109 E-4/Trop "Schwarze 8" of Oberfeldwebel Werner Schroer (8.Staffel / III.Gruppe / Jagdgeschwader 27) above the North African coast of Ain el Gazala/Libya, April 1941. The aircraft is wearing a short-lived leopard camo scheme. The mottle is definitely sprayed free hand but the job was done very carefully and skillfully. For example the mottle extends onto the canopy framing so the canopy must have been carefully masked. These aircraft had lower surfaces in RLM 78 and upper surfaces in RLM 79. For the mottle itself, some expert said that it's RLM 80 but there is a distinct possibility that it was not an RLM colour at all but rather an Italian paint. It was dark green anyway. The leading edge slats were completely independent of all other surfaces and each other. They had a mechanism which caused them to deploy automatically at low airspeeds. As the flaps would only normally be deployed at low airspeeds it is likely that the slats would also deploy but they are not linked so it is possible for one to be up and the other down. They would usually remain deployed whilst taxying as well but it was common practice for ground crew to push them back up on parked aircraft to minimise the chances of foreign objects getting in to the mechanism.This means you can display them either way. If the slats are down the area at the leading edge of the wing revealed would usually be in RLM 02 (primer). The Luftwaffe suffered high rates of attrition in the conditions of North Africa. The Bf109E did have a tropical filter fitted, as did later Fs and Gs. It was cleverer than the British solution as it's frontal area is no greater than the standard intake. There was no drag penalty. Also it could be opened and shut. On the ground or at low level, in the dust and sand, the air intake was closed so that air was taken in through the filter medium. Once clear of the hazard the intake was opened and air flowed directly into the engine. This means that the filter wasn't strangling the engine. It was all operated by a handle in the cockpit.