I would have the seat repaired by a local upholsterer and re-dyed to match the existing. You can send a sample to Colorplus (Surflex) and they will mix a dye to match your existing, aged leather. Many concours guys have gone this route with extremely positive results, as we have several of the the top National competitors/judges in our PCA region.
SURFLEX(CUSTOM COLORS) : :: Color Plus ::