Here's the Palm Readers lightened inner door on his 68' Coronet.
Lots of care and patience went into making all the holes and trimming to present a stock look. Note the carefully hole sawed window crank bridge behind the door skin.
This can be done to almost any door with care being considered to where the regulators are and the ability to function as the factory intended them to do so. My previous lightened doors have a crude version of this method to them and yet all the windows, vent wings and latches work as stock.