I also had a similar problem when evaluating a book. I contacted a specialist. I think you need to find a professional appraiser. The book may have various damages (rust), which are only on staples or also on paper. I doubt that the forum will be able to give an accurate assessment of the book. Several articles have been written on this topic, with the help of the plagiarism check service fixgerald.com I even prepared one article for an online magazine. But this is all theory, only a specialist will help you understand whether the book needs to be restored (sometimes restoration will be more expensive than the book itself). Although if the book is valuable and after many years you sell it for a lot of money, then restoration can be profitable.