I've seen them. The AEM-7 has been there for a couple years now. From what I was told, it got shipped to Riverside with instructions to evaluate it for overhaul. The shop forces at Riverside, having never touched electric motors ever, supposedly reacted along the lines of "What are we supposed to do with this thing?" and shoved it into a corner out of the way... where it remains today.
"CSX Detector. Milepost Six Point Four. No Defects. Repeat: No Defects. Total Axles Seven Four Seven. Detector Out"