Changing a 63-65 Rivera is almost a crime, except maybe for slight lowering and a nice pearl paint job. The song pretty much sums it up. *LINK*
"C'est si bon" (pronounced [sɛ si bɔ̃]; transl. "It's so good") is a French popular song composed in 1947 by Henri Betti with the lyrics by André Hornez So do a little fox trot and don't mess with it too much. The graphite color would work.