FWIW I think the majority of 52s were RLM 70/71 upper surfaces with 65 lower. This would apply to the parachute drops over Belgium in 1940 and the drops over Crete in 41'. However the early ones (Spanish Civil war) would have been in 61/62/63 uppers with 65 lowers. I believe one of the pro-modeller versions gave this color scheme. I have never seen a 52 in desert scheme. If there was a floatplane conversion kit to do one of the aircraft that attacked the bridges over the River in Holland you might have a 72/73 over 65 scheme. I would love to do that conversion, but those floats???
Bill Shuey