Apple Photo Books

Only if you saved the book as a PDF can you get a reprint. When migrating from iPhoto to Photos projects, i.e. books, were migrated as albums since Apple discontinued the Print Products that they offered.

If you do have a pdf of the book let me know and I'll post how to get a reprint of it.

Apple has been saving the books only for a few weeks after you placed the order, but the Apple Print Product stores have ben closed - the last orders had to have been placed by September 30, 2018. You will not be able to access your old order. It is much too late.

They might be somewhere in your backups. Is there a way you could provide more details?