The Antelope Valley Airshow at Edwards AFB last year gave access to some very unusual airframes including some unique types. In the 90s, an F-16D airframe was converted into a variable stability testbed. It was used for test pilot training but also became a testbed for other technologies. Known as VISTA, it also tested a thrust vectoring nozzle on the engine as MATV, performing some amazing maneuvers. I know one of the test pilots that flew it including when it misbehaved!
The aircraft continues to be used for new developments and, relatively recently, it was re-designated to be an X-plane. It is now known as the X-62 while continuing to perform some of its original test pilot training roles. It was on display in one of the hangars at Edwards. It was a bit hard to get good shots of it since everything was rather crowded, but I was able to get a few that I was happy with.