Ignition switches
The 4 without the lock cylinder appear to be the '69 only switch. They made both 5 and 6 terminal versions. Check all for tight terminals, good bezel threads, and also the hole that holds the lock cylinder in place. Another area that fails is the plastic plate inside that the lock cylinder tang engages. That slot can chip and/or wear. Of course, without the lock cylinder, you can't really test them either mechanically or electrically.