One of the things I was interested to see at Moses Lake was the new testbed being fitted out for Rolls Royce. Rolls currently has a Boeing 747-200 that they use for airborne testing of their engines. I shot it at Tucson and posted about it here. They recently acquired a 747-400 from Qantas to use as a testbed and it was moved to Moses Lake for conversion by Aerotec. I don’t know the timescales for the conversion process but it will be interesting to see it when ready in house colors and hopefully with a big engine installed on one of the inboard pylons.
Before the F-16s became the drone target conversion of choice for the USAF, the F-4 was the jet. The contract for conversion was run by Tracor which ultimately ended up being part of BAE Systems at the time I saw these jets. They did the conversion program at Mojave Airport in California. We were a bit of a distance from the ramp where they were parked but it was early in the day and the heat haze was not yet a problem so a long shot was feasible. Looking at these, I think they were both RF-4C jets that had either been converted or were about to be.