Don't forget it's a British car. It has spade lugs for everything except
the really critical connections that are in all the places where they'll
collect moisture and dirt. They use Lucar (bullet) connectors for those
because they're more likely to fail and they trap moisture better.
The ignition switch has spade lugs on the back. If the female parts that
are plugged onto it (specifically the brown and white circuits) get
loose and/or dirty, then they can heat up the switch to the point where
the plastic softens and then your switch won't work properly anymore.