Weren’t they also called “Der Schokolade flieger(sp?).
Look at the writing on the hull of the airplane in post #9. It's partially obscured, but obviously reads, "Rosinen-Bomber."
In more than four decades in German, always talking with older folks about their war experiences, I've never encountered any expression other than "Rosinen-Bomber." (However, I'll confess that, lately, there's almost no one left with clear memories of that era.)
My son's schoolbook likewise mentions "Rosinen-Bomber."
Me-thinks moderns can't imagine how vital simple foodstuffs like multi-purpose raisins would have been back then, and in contrast how impractical chocolate would have been (like airlifting caviar into a famine area), so in their minds they substitute something fancier.
The expression "Rosinen-Bomber" - while not exactly a play on words - is also reminiscent of the familiar expression "Korinthen-Kacker" (which has an entirely different meaning).
Regards,