Its fortunate that you never owned a classic SL or vintage Rolls Royce or Ferrari. ALL cars go through a period of depressed value. You know those $100,000+ SL's you see at the car shows? They hovered around the 5K mark for a while before their real value was discovered. Those Multi Million dollar Ferrari's did the same. While its unlikely the 140 will ever see any real collectable value you never know what the market will do. The value may eventually rise as the market learns to appreciate its build quality because of the absolute crap thats being produced these days.

Butchering a car because your too cheap to pay for replacement parts is a really sad thing to do. If you want to tinker go build yourself a heathkit tv or something as you might learn something in the process. Putting cheap replacement parts on a car is not the greatest thing in the world but its leagues better than what your planning. By the way guys have you done all the calculations on the resistance changes your harness will cause? Do you have a schematic of the car so that you can use the correct guage of wire and wiring that will take the amperage? Found a solution to provide the same RF shielding that the original harness provided? Price some of the computer modules for your car before diving into your project and decide if you want to spend the money in the event that you connect a wire in the wrong place. Theres a lot more to the process than connecting a bunch of wires with wire nuts in your garage.