I would get a blank book like this and see what you can do to maybe make it fit and look nice?
You'd most likely be de-threading the pages from the hardcover and sewing your own story in.
Here is a very inexpensive one, and hardcover! You could do a book a day!
These are cheap. Plain, but cheap hardback, blank page books. https://www.amazon.com/Ashley-Productions-ASH10700-Hardcover-Length/dp/B01J19YXVM