From memory: Boeing employees in the late 80s got together and restored the only surviving 307 Stratoliner (a pre-war B-17 civilian variant) to flying condition, including the ever-so-rare interior. On its second, maybe third flight (say, 1996), something went very wrong with the fuel system, and to save their lives the crew bellied her into a lake off the end of a runway, ruining said restoration. The fished her out, re-did it all again, and then flew her straight to Dulles, where she remains parked to this day.

I only wish they could figure out a way to tour the inside.