One thing you asked was about the wiper transmission.
The wipers motors are wired inside to provide different speed depending on which wire windings are powered, so there is no physical gearing or transmission except for where the motor itself drives a worm gear setup to move the lever around in circles.
Speed are all determined by which wires the switch sends power to.
I know it would probably be a pain the behind at this point, but I'd bet if you pulled the stuff you had questions about and posted pictures, we could tell you what you need.