I’m with Don and Bob. Unless your car is missing all wiring and you want to add some unusual modifications, going with the basic stock configuration will save you money, time, and effort. Particularly years down the road: you already have the Shop Manual and schematics to trouble-shoot. These harnesses have lasted 50 years without that much degradation (except from previous owners butchering them) and with care can last another 50 years. Some harnesses are not worth restoring (e.g. alternator and engine gauge feed harnesses) but are readily available as reproductions.
I’ll even tell you to buy them from Don instead of me. Support your local vendors and craftsmen!