Possible Clues:

• Continental movers
• Dead in the postscript, and that's flat
• Dental items
• Not in time to get into the postscript, and that's flat
• Not in time in the afterthought, and that's flat for them
• Taking form of exercise, I lost dentures
• Not in time to be in the afterthought, and that's flat
• Postscript about the dead, and that's flat
• Items of crockery
• Lenox products