Very annoying: the driver's window would not go up or down. There was a clicking sound from the motor, but nothing else happened. Obviously something was jammed.
But there were clear signs water had entered. This speaker was completely perished too.
The motor itself was even rustier. Definitely not designed for repair.
So now we need to look out for another motor. I decided to transplant a rear motor to the driver's door. I was happy to find the motors themselves are not handed, though the motor and lifting mechanism are riveted together and sold as a unit. So there was more drilling of rivets. I could re-assemble everything with nuts and bolts.
All fixed and ready. The door panels in place and the window goes up and down on the button.