When I first got to Nellis, A0751 was the 57th WG jet. Falcon AMU traded A0751 (along with several other block 40s) for most of Viper's block 50 D models. A0751 is now an aggressor and is painted in the aggressor blues.
Falcon AMU got A3927 from Viper along with several other D models. I crewed this bird for a little over a year before it crashed. Pilot reported the jet was stuck in AB and ended up running out of gas about 300 yards short of the runway (it actually landed short of perimeter road by only about 50 ft).