A few years ago I was restoring a 68 GT S code fastback. It was pretty unmolested, had been sitting since 1980. Texas car, so it was rust free. Under the front carpet and underlayment was the build sheet. It confirmed all the options on the car. There was a good sized lump under the carpet in the pass. side rear floor. When the underlayment was pulled up, a never installed interior door handle was laying there! Under the rear seat, imbedded in seam sealer was a handful of nuts, bolts, screws, and a couple of interior fastback brackets. oh, also about .50 cents in change! pretty interesting what went on during assembly.