Never Built: Lockheed CL-1201
foundandexplained.comI guess the weight of the documentation never exceeded the lift capacity so the place was never built.
Lockheed's Skunk Works was famous for having a very streamlined process. U2 monthly reports, for example, from Kelly Johnson (Lockheed) to Bissel (CIA) were 5 pages. Per some books, it was only because of poor quality control over titanium parts for SR-71 ("A-12") that Johnson agreed to put in place a typical papertrail process. (Fun fact: we got most of titanium from USSR via shell companies. The Russians thought it was for making ovens.)
The titanium story was classic. I think the cover story was bicycle frames.