LoL about exact location of build sheet. Not because country_ck asked the question but because there is no "exact" location. Besides those already cited, I've found them between the springs and upholstery of the rear seat back rest and, sadly, in other cars.
One of the things I have used to get history for old cars is to do a title search. Following registrations of the car backwards from your title will let you find out POs as well as mileage at the time the car changed hands. Most state DoTs can provide for a few $s. When you write, make sure you have the VIN correct. The search engines are not helpful when a digit is missing or out of place.