It is correct to have undercoating. Jim Osborn reproductions publishes a reproduction of the Body, Trim & Sealant assembly manual and in there you will find the factory assembly instructions including sound deadener. Although many do not undercoat their cars when doing frame off restorations ( myself included ) some is recommended. The inside top of the front fenders need to be undercoated to prevent a rocks kicked up from tires from dinging outward the top of the front fenders.