I had a Original Lobo once upon a time and had collected both kinds of the small elliptical coils - wide scan and concentric. These are the 20kHz ones with male pins on the coil wire end and receptacles on the detector connector.
I sold the lobo and eventually the coils.
Well, now I have a Demon II and it takes those same coils. Anybody out there with one hanging around, I would be interested.