I was active duty Air Force in the mid 00s, and we had a tropospheric scatter terminal called the TRC-170 where the entire manual was reverse engineered. Air Force Technical Manuals aren't the most riveting of documents to read, but man that one was painful. The technology is badass though, and still useful even half a century later!

The story (which I have no idea if is actually true, but it was widely repeated), was that the engineer who built it in the 60s didn't get paid the full amount that he thought he was owed, so he destroyed the technical manual as a middle-finger to the Air Force.