Ok so I tried to draw you some diagrams, but first I am a shitty artist, second, my camera died befor ei could take a picture of the front of the mast, so I'll have to try and explain it. This is just the way that I have things set up. The picture is of the 6:1 downhaul. The front of the mast (unfortunately couldn't get my drawing) Has a 3:1 jib downhaul, There is a block at the end of the jib wire, and the rope halyaard is tied too it, it runs down through a cheak block on the mast, then back up through the block on the halyad and then cleats too a jam cleat on the mast. This makes it adjustable while sailing. Also you will need a cleat to keep track of the end of the main halyard. This doesn't have to do much, because it is your downhaul that provides all the control of the sail. If you have a rotation inhibitor(can't rememberif you did or not) Then the downhaul setup is run on the inside of this. The downhaul is easier if you have one of those hinged cleats on the mast so all you have to do is pull straight out. Also, i agree that the cleat on your beam is most likely for your furler. To do this setup you would have to add some stuff to your mast, it probably doesn't have to be this complicated, and you of course can adjust things any way yoyu like. But this should give you quite a bit of control on your sail.