This is a list of the major components within the door (front passenger side shown):

Window regulator (note, the rear window regulators are designed differently and are not immediately visible)

Door lock vacuum actuator, early style (does not apply to driver's door, which is equipped with the master vacuum switch instead, see attached picture). On later W123's, the actuators are in similar locations but look different.

Door pull

Door latch and lock mechanisms

Master vacuum switch (driver's door). Note that on later models the master switch will be oriented vertically instead of horizontally.