Dave, I've replaced my under dash harness and trunk wiring harness in my "73 Cuda. I bought both at year one. There is only one company (I believe) that makes repos of these harnesses. I was pleased with the quality-Plug and Play. I got mine at Year One. As you may know, these original harness do not do well over time and can cause fires. Replace them all. I still need to do my engine harness and headlight harness. They all can be found at Year One.
Hope this helps