Possible Clues:

• Indulgently lavish
• Self-indulgent English scoundrel overwhelmed by depression
• *Just OK
• Respectable clothing in the current era is in decline
• Decanted (anag.)
• Last month, F Prefect’s friend becoming corrupt!
• Ten years associated with heartless nest, corrupt
• Ten years rent is only the half of it, reflecting what's in moral decline
• Overripe
• Act ended unfortunately in decline