In the early 1980s, I was visiting my parents in Florida. Their land lies close to the Eglin AFB Reservation.
Late one evening, about dusk, I saw a quiet jet fly over at a low altitude. It had rounded wings just like the fake model stealth fighter which came out about then.
When the real one showed up it looked nothing like what I had seen. I still wonder what it was. It was not an F-4.
I had a Marine friend who did several parachute jumps over Elgin. He said there were hangars scattered out in the boonies away from the main base. During the day they were closed up and almost looked abandoned. At night they were lit up and all kinds of activity going on. One time going home from Mexico Beach, Florida to Mobile, Alabama traffic was blocked for several minutes on Hwy. 98 by Air Force MPs outside of Tyndall AF Base. They would not tell us why but the only thing it could have been was an aircraft they didn’t want anyone to see. As I recall we were held up for about 15 minutes. We never heard anything.
Could have been a prototype that didn’t make the cut.
Was it this?
https://www.alamy.com/stock-photo/vulcan-bomber.html
Sounds like the F19, that they may or may not have built.