Just a handful of stainless screws for attaching P23/62 the upper hatch seal.  The aluminum bars (3 of them) have counter sink holes for these babies to go right into which will keep your seal in the right spot.  If you are missing the aluminum bars you can buy 1/4 x 1/8 stock and counter sink the screw holes for a nice flush fit.  Make sure you bend the new bars as you go 'cause it'll make it a much easier job.  Curved bars on the sides and a straight at the top.