Diesel Bombers - 1989 W250 Project! Help Needed!

Hey guys I recently purchased a 1989 Ram with the 12 valve mechanical Cummins. Body was shot but I have a good cab and box off my current dd which is a 91 W150 with a 318.
The cab is now off the frame and its been sanded and prepped for primer and paint.
However I will need some help regarding electrical and tranny cooler lines!

I have two lines that run from the cooler down along the frame rail where they are then cut. The transmission only has 2 lines coming off it which run to the block mounted heater.. Where would these 2 cooler lines along the frame rail tie in?

Second, the cab I am removing/removed was jammed with options. How would I go about removing the rats nest under the hood? I would like to keep my important wires/sensors and eliminate all the junk.

Any help is appreciated. If I can ever learn how to load pictures I will post the progress!