Possible Clues:

• Bowlers and trilbies
• New Year's Eve party purchase
• They may be cocked
• Symbols of office
• 'The 500 -- of Bartholomew Cubbins'
• Quotation ends
• Different roles, metaphorically
• Milliners' output
• Stetson and stovepipe
• 'Porkpie' and 'pillbox' attire