When listing a mongrel box of unknown providence it helps to have a keen sniffer. Elsewise when faced with shipping a smelly book and a getting a smelly Amazon feedback, the seller may be obliged to issue this plea:
Dear buyer: As I began to package your book I noticed a moderate musty odor not disclosed in the listing. I apologize for the oversight and realize that you may not want the book in this condition; however, I offer a $10 adjustment if you accept the book as is: otherwise I'll have to cancel the order. Please inform me of your decision.
Thank you, Dennis Thompson aka Mr Koreander.