by Karl von Salzen
68 are one-year-only: they used pushbutton
handles [ala 67] and the lock knob is on top of the
sill.
69-70 are the same, lever action door
handles and lock knob is now a lever above the inner
handle.
68-70 are L code keys.
71 and started the vent system thru the
door: slots in the leading edge and the slider in the rear. 71 and
up are R code keys.
68 to mid 76 hinges are the opposite of
mid 76 to 79 hinges.
Around 75, the lock knob moved back to the
top sill like the 68 door. But the 68 door does not have the front
air slots
