Casebooks are only useful to give you a rough sense of what the interviews will look like and what you have to do. Actual cases do not matter by the way, so they are all equal in that respect:. A math exercise will have a single right answer, and often a single right/best way to do it. Not so with the cases. These casebooks are just tools, a means towards an end. If you have a case book, any case book... you are good to go.
Now, the one thing you need to do to prepare well, is find someone who will give you the specific, relevant, actionable feedback YOU need to improve.