Stem and headset came off fairly easily, will clean the headset thoroughly before passing final judgement on its fitness, but first impressions are good, no obvious signs of excessive wear or pitting. Regardless I'll probably replace the caged bearings with loose balls when I reassemble it. Externally much of the surface rust seemed to fall away during the removal process, the worst piece being the top nut which may need to be replaced if it won't clean up.