Possible Clues:

• Hershey's __ bar
• Old PM sets scene for witches' encounter with Macbeth
• Ledger with lines
• Joker player Ledger
• Moor yacht -- that was his hobby
• Former prime minister
• Sir Edward --, British Prime Minister (1970-74)
• Open land with scrubby vegetation
• On which a weird trio met a former prime minister?
• "Ned Kelly" actor Ledger