That's Hare-brained. A Hare is a Rabbit BTW.

Its' a bit of a pain but doable.Don't change the doors unless you are going to repaint the car.Also you will need the armrests front and rear along with the door panels.One more thing,when changing to pw you will need to add the "blue" screw holder to your old door.The manual armrest attaches with one screw but the pw armrest has 2.This will be more obvious when you remove the door panels on both cars.Fishing the wires through the doors is also alot of fun.Don't cut any wires!

The power window looms on a 200 are entirely separate from the main wiring harnesses in the car. You can unpick everything from a donor car and install it into another car

If you get all the parts from the donor car, it should be straigtforward. I wouldn't swap the doors. You have to remove the glass and scissor assembly and swap them with the motor. There should be a complete wiring harness in the donor car that when removed will yield all the relays and associated wiring. I hope you have the wiring diagrams for both cars, that will make it easier. You will also have to swap out the arm rests. All that being said, when I had the opportunity to swap out the roll ups in my '87, I opted not to because they are simple and reliable and last forever.

It's not a bad job to swap the manual and power units--I did it on my '87 240. I wouldn't try to replace the doors. Old Sven hangs 'em right, with his $100K machine (big soft suction cups, adjust by 1mm increments for yaw, pitch and roll). Hard to replicate that on you own--you get hard closing, more wind noise, ask me how I know. I think you can swap the improved seals over.