If you want something that looks close to original and will not dry out and crack, use SRML type wire available from Belden, Carol and a variety of other wire manufacturers.
This wire is has a silicone insulation covered with a braided glass cover. Fine strand coated copper and is flexible too. I have seen it in White, Black and Red. It lays nice and makes great harnesses, although working with the glass braid insulation makes your hands and fingers itch!
SRML
