[dsraven]

I am with softpatch on this one, show truck? numbers match restoration? if not, why not buy a kit or rewire it yourself from scratch? there isn't that many circuits and a stock harness wont be much better than you have there. access sucks but if you remove the speedo and glove box it gets better. get yourself a good pair of crimpers if doing it yourself and make sure to pull on every crimped connection to ensure it is gonna stay put. use double wall shrink tube on anything that will see weather or dampness, use some sort of loom to keep things tidy, or tape harness but that makes it harder to find any issues that may come up in the future. they make cable ties with holes for screws or you could use clamps.
you can do it if you just start with a fuse block and do a circuit at a time, soon you would be done.