Dunno about the rest of it, but you could try soaking the forks/headset etc in penetrating oil for a few days and see if that helps. WD40 is just a solvent after all. Maybe heat them a bit too to expand the metal.
@jonlubi started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Dunno about the rest of it, but you could try soaking the forks/headset etc in penetrating oil for a few days and see if that helps. WD40 is just a solvent after all. Maybe heat them a bit too to expand the metal.