I have looked for the build sheet in my 73 Challenger. Checked under the bucket seats, removed rear seat, under hat rack, around rear of glove box to no avail. Tomorrow, I am removing the bucket seats and console to remove the original carpet to install new carpet. I'm hoping the build sheet is there. If not, I will remove the door panels. I am very interested in finding it because other than the window MSRP and build sheet my 73 Challenger has eight of the possible ten places a vin number is on the car at time of sale. Also, the intake manifold, exhaust manifolds and jack all have correct part numbers/dates. I believe the engine only has ~87,350 miles. Today, ordered Gabriel shocks and radiator hoses from Summit to replace what I think are the original. I had no idea of how original this Challenger is when I recently bought it.