I just came across your post and you may have found someone to wire your vehicle by now but if not allow me to introduce myself. My name is Peter Fishering, I specialize in the wiring of American vehicles up to 1972. I came upon this site while searching for parts for a customers 68 GTO. Please check out my web site at
www.wiringbyfish.com or call me 909-503-3068 if I can be of any help.