Foreground: North American P-51D-5-NA Mustang, serial number 44-13882 "UNO-WHO?", flown by Maj. George Lamb of 356th Fighter Squadron, 354th Fighter Group, 9th Air Force. Lamb is credited with 7.5 aerial victories total, with 2+1 unconfirmed in this aircraft.
Background: Focke-Wulf Fw 190 D-9, Werknummer 600424 (the 737702 visible in post #1646507 is, as far as I know, fictional) "Red 1", flown by Lt. Heinz Sachsenberg of the airfield protection squadron of Jagdverband 44. Sachsenberg is credited with 104 aerial victories total. I don't know any German, but according to Wikipedia the text on his aircraft reads '"Verkaaft's mei Gwand I foahr in Himmel!" meaning "Sell my clothes I'm going to heaven".' Also, the red stripes on the bottom were for the airfield protection squadron to identify themselves as friendly to anti-air gun crews.
I don't know if the two ever fought - the information I've found from quick Google searches could go either way. I'm sure someone with more knowledge of WWII stuff would know, though, especially since JV44 seems to be a pretty popular subject.