Year One has a deal with the only producer of quality harnesses. Search the board, there are lots of threads about this.
I lucked out on my 73 with only good cleaning and re-wrapping needed for the engine and lighting harnesses under the hood.
The dash harness had some petrified vinyl in it from overheating but you can score non-Rally harnesses pretty cheap on ebay since a lot of dashes have been converted to Rally. Just swiped the wires out of the used harness and re-wrapped them into my survivor harness.
Craig