The auto electrical stuff can be a pain but mostly it is labor rather than expensive parts.  Old cars need a fair amount of attention focused on taking care of them (electrically) and small problems can be a really big deal in reliability. Also, electrical problems tend to compound - two small problems by themselves aren't much but together can be a show stopper.

Here is a simple example of the kind of problem you get with old cars. The pic above shows a place where time and constant engine vibration managed to break through the wiring insulation. In this case the wire provides the signals to control the ISV, which is used to control the idle. This small problem put me walking on a cold night in January. 

The Porsche electrical connectors of are pretty low-tech and several of mine need to be upgraded.  In the process of removing the engine, I broke this sensor connector. It was very brittle; these cars are known for high under-hood heat levels and the connectors for these sensors are one of the usual casualties. The other part of this connector as well as the other sensor connectors are also brittle.

One final comment on electrical stuff - Zip ties.  Above are the Porsche original and a substitute that I stumbled onto. My concern was that the substitute (which costs approximately 1/10th that of the Porsche zip tie), would not hold onto the studs that are provided around the engine bay.  A more creative guy could make these alternates work but if you get a chance to buy the originals, get them.