Not always does someone have the answer. I'd suggest with the exterior color you are going with, be careful to have someone reputable with this. I have a 70 Delta 88 that I went back with the color code of copper. Took the body man 3-4 times to get what the original color was.

If you need further help with your 66, might check antique chevy forums, not saying you won't get help, but again your talking about a car that's 50 years old. Some here are "knowledged" in the old stuff as an old guy should be, but be persistaint, and understanding.

 

Painted