HI,
Using thick border line as quide, The images can be made identical in design for easier to crop.
I will create a .Net class for you with a function,. It will take the image/file as a argument and map and crop the page part of unique size and design.
I will complete and test the function in a day and send you for testing by tomorrow.
You can test them on your images and see if any problem.
I will resolve the issue .
Thanks