No, there was no gasket or spring on the flip-top part with a factory locking cap. The gasket and lock were in the cap itself, which goes on the filler neck like a normal fuel cap. The rubber you see on the auction piece is to keep the locking cap from vibrating and making noise. The part is 100% complete and correct as shown, but you still need the cap to fit beneath it. In this case, the flip-top part is just a cover for the actual gas cap.