HI Connie,
Remember that nearly every '66 has been repainted at least once by now, so don't worry about "special" or rare colors. Either repaint in the original color, or pick something you like, regardless of its rarity or non-existance in the 1966 color palate!
I'm personally very partial to vintage burgundy, but I also like the metallic green, which was a late year addition to the available colors.
Hey, where in NM are you?
Steve