Well I got around to stripping the parts off the frame (all went well except for a dropout adjusting screw, I had to hacksaw the head a bit to keep the screwdriver engaged). The previous owner apparently had the original french headset replaced with an english threaded FSA headset. The locknut came off okay, but the threads on it are marred. The adjusting nut came off okay also, and seems fine. Should I look for a french locknut and use the rest of the FSA? Or just replace the unit - Velo Orange has french headsets. I doubt I will look for a Zeus headset.