OK, I'll toss in the Horten Ho 229, which was an emergency fighter derived from a glider, though originally intended to be a bomber. The German emergency fighters weren't so much designed in case supply lines should be cut (Clue 2); they were more along the lines of "things are getting desperate, so let's do fast and expendable." So I'm not sure this one fits the early clues well, but it's worth a try, I guess.