Just think, it, the B-52 was designed just after World War II. BTW, I remember in 2003, they tried to duplicate the Wright Flyer using computer aids to fly for the 100th anniversary of the Wright Brothers only to have it flop and not fly. The Wright Brothers had only 1903 tech yet they made theirs fly. Come to think of it, I think the first true stealth plane was made out of wood, the British Mosquito.
Yes, I believe you are correct. The Mosquito was made of thin plywood because of an aluminum shortage. It would have been nearly invisible to the limited radars of the period.
With modern radar there is no such thing as true stealth. Nowadays, stealth just means you can get closer before detection...this can be a very worthwhile edge.