Possible Clues:

• Head profits from a form of taxation
• Result of appreciation
• Cardinal's heartily against making profits
• Everywhere bar London loses from this tax?
• The sort of profit made by London?
• Profit from post-war Honolulu and Juneau for US?
• One pays tax on these - as must happen when money flows into London
• Seat of government's acquisitions?
• Profits from investment sales
• What this puzzle's circled letters are with respect to the surrounding shaded squares?