Possible Clues:

• Wood preservative oil
• Preservative liquid obtained from coal tar
• Oily, smelly wood preservative
• Preserve wood in Greek island full of love like this
• Preservative substance made from wood tar or coal tar
• What island stocks is old, therefore preservative is the answer
• Scooter treated with European wood preservative
• Coat to protect sailor, old, visiting island in Med
• A wood preservative
• Island protects crowns of old stone obelisks with this material