They supplied a top part to the fuel filler tube that bolts to the body. Many have gone with a different setup that has the cap and the tube as one piece.
http://lnfletcher.homeip.net/66Cobra/gascap.html
Holes up or you will have trouble getting the roll bar on and off for body fitting.
http://lnfletcher.homeip.net/66Cobra/rollbar.html