You have the old style main sheet that attaches to the boom in two places. The vang attachement (4) is not used any more. Most people cut it off to keepit from nailing someone in the head. Take the boat to your local Hobie dealer for help. They will know where everything goes and will have any hardware you need.

Your hull sides do look awfuly wavy. Are they solid? Hull and deck delamination is a huge problem with the H16's, and it can be a blat killer. I had to replace the starboard hull on the boat I'm rebuilding. Good luck!