Unless a dealer has a trim shop it is unlikely that they would carry any leather. Yarwood ( not Yarnold) stone is a fairly common colour so you might find Alon White, Williams or Melvyn Rutter for example, might have some off cuts. Otherwise you are into buying a hide...which isn't cheap!
Other sources might be able to match up the colour but not nessarily the grain and suppleness of the Yarwood leather.
