Your first photo shows the loose end of the rod hooked onto a bolt. Said bolt has two sides that have been machined flat.
Your second photo shows the flap with a hole in the middle of it. The hole is the same shape as the bolt on the end of the rod.
Close the flap a (against the spring tension), and pass the bolt through the flap. With your third hand, find the spring washer and nut (that I can't see in the picture) that fits the end of the machined bolt and screw it on. From memory you don't need a special bolt, not sure if a 'Nyloc' nut would be a bad thing.
When the Charlotte docks you will get a proper answer from downunder........
Joe R