Possible Clues:

• Duchy
• Plaza-Toro's domain?
• Highest rank of the British peerage
• What peer has, back from old country with retro-style fashion
• Old penny given here - a custom arising in duchy
• Wellington's rank
• Duchy out-moded in United Kingdom
• Across the nation, celebrated at last with style, raised to peerage
• Thus one is entitled to make a dud moke of it (7)
• A penny given to the country - custom arising in duchy