Possible Clues:

• The last thing read by one reading book in established gin den
• Closing time perhaps in established gin den
• What Rag and Tag do, but not Bobtail, for a finale
• For most of 3 down, has gin cocktail at closing time perhaps
• ... until penny drops close
• Denouement unresolved, page missing
• It's a wind-up for half of 9 across in Government
• Conclusion needs fixing, though not at first
• Closing
• It's a wind-up at the closing stages in Government