Out of the "Box"

In the world of IPMS (where the "P" stands for plastic) there is a category called Out of the Box. In our world of paper it might be called "Out of the Book". Basically, you build the model with only the parts that are contained in the box! I know that some paper modelers add details using plastic, modelling materials, clear canopies, brass/aluminum rod, etc.. I like to cut out the printed, and shaded, windows and place clear plastic behind the frames. But this is not,strictly, "out of the book". Currently, I'm trying to stay true to the medium: eg. by constructing paper buckles and snaps for the seat safety straps in aircraft. So..oooo the question becomes, how close should one stay true to the material (paper), and how much discipline does it require to keep it "Out of the Book'? Thoughts anyone?