My sister, whom is going into her third year of Japanese in college, translated the link you posted and said that this is a book that shows original, unedited comics from their very first publications they were in and compares them to their republications. The comics covered are from "Astro Boy's first appearance".
It appears those changes are edits to the manga or deletions of certain drawings due to the fact that those things might have been discriminatory at the time of republication in whatever format it was. They also might have cut out certain panels for newspaper serialization to fit the strip in the newspaper, or re-arranged the stories to make the story consistent and flow better.
The second user review in your link says that there are also annotations from the author.
Seems like an interesting book. I wouldn't mind checking it out myself if it were in English.
EDIT: I think this link says what chapters are covered in this book.
