B-26 .... hummmmm, now are you talking the Martin Marauder or the Douglas Invader?
High speed and maneuverable? Could they turn essentially 90 degree corners at multiple mach speeds?
Capable of changing altitude by 15 miles in a second or so?
No visible means of support? They had wings didn't they, albeit relatively thin, high aspect wings, but wings none the less.
Propulsion was obvious and traceable even with the technologies of their own days.
Guess I'm not understanding your comparison here?!?!?