Possible Clues:

• Gargery regularly showing signs of age?
• Noble PM, between 11 and 26
• White-haired — horse
• Lifeless person in GS's post earlier
• Dreary shade (Var.)
• 'Pardon me, would you have any ___ Poupon?'
• Medical drama title character
• Neutral shade in London
• A horse for Lady Jane
• Jane or Zane