I slid my 69 camaro RS into the back of a Sebring convertible a few years back and I can feel your PAIN!!
Dont worry, it's just sheetmetal and money..
I also found my buildsheet in the 1975 Grand Am on the gas tank, it was not in too bad of shape actually! They (GM) did not mean for these to leave the factory, they were simply a way to ensure each worker at each station got the proper equipment iinstalled on the way down the line. That's why they are made of such thin paper, they were not supposed to survive. And they were not supposed to be put in the car either. That was just lazy workers not wanting to take the time to throw them away! It was just easier to stick it somewhere after you were done with it than walking to a trash can.
Tat is why you almost always find them in the last parts to be installed on the car . Like the gas tank, under the rear seat, under the dash, or in the fenderwells.