Romanian Messerschmitt Bf 109E-3 "RICA", interesting detail, on the wings upper surface the yellow bands of pre May 1941 markings are still present (underside seems completely repainted blue), on the left no. 23 of 7th Fighter Group. Karpovka, Stalingrad - November 1942
Seen a line drawing that looks very similar connected to a Ju 52 by three hoses and described as a
‘German Aircraft Engine-Heating Device’
The method generally used to heat the engine is to cover it with a heavy canvas hood and force a draft of hot air into the bottom opening. To do this, the Germans use an engine heater (see fig. 7), which can warm an airplane motor within 15 to 20 minutes, raising the temperature of the engine approximately 50 degrees. This device heats air by passing it over burning vaporized fuel and then blowing it through double-walled canvas tubes into the hood placed around the engine. The blower of this apparatus may be operated by either a gasoline or an electric motor.
From Lone Sentry
"Winter Flying Problems" from Intelligence Bulletin, February 1943
http://www.lonesentry.com/articles/intelligence-report/winter-flying.html
I also tried to identify the engine heater but with no success. I’ve seen the device in German and Romanian WW2 photos, unfortunately no additional info about the exact model and manufacturer is provided. If anybody knows some details please share. Thanks!