Flip-up farm book

Sometimes I feel bad for my daughter when it comes to our household books.  Big brother had all the fun flipping and tugging and pulling all those interactive things you find in books.  He also had some fun chewing and tearing and, in extreme cases, shredding into tiny bits, those interactive things you find in books.

This was one of his favorite board books.

"Who says oink?"

"A PIG!!!" 

He loved that.  

He also ripped off the flaps of some of the pages and the background of another.  I always try to watch to make sure he treats books well - but my success rate wasn't great back when he first got into books. 

This is another of the books I really like that isn't in great shape. The binding is really loose.  I picked it up from the thrift store because I liked the pictures.
  

For my daughter's first birthday a few months ago, I decided to combine the books to make something that was still fun for her, but wasn't so easily destroyed.

Here is my Flip-up Farm Book. 

It has the same lift the flap feature, and though not quite as illustrated, is a little better in baby hands.

 

I took pictures to show how I made this book, but I've been unable to find the measurements I used.

Is it wrong to assume that if you are the type of person that is going make one of these, you probably know how to just figure it out without my help?

I always assume that.

Let me know if I'm wrong.  I'll make a tutorial.