Relative to the build sheet: sometimes, if you are lucky, and depending on the build plant, there may be one stuck in either the seat back or the seat cushion bottom. There was not a requirement to leave one in the vehicle so it just depended on how lazy the person was feeling that day, whether they left it in there or decided to throw it away.
Depending on how desperate you are, you can also send the GM Heritage Center Archive $50 and your VIN and they will send you the vehicle invoice specific to your truck, including your original options and pricing.
Invoice:
http://www.gmmediaarchive.com/?page=3