Congratulations on the new purchase and welcome to the cat community.

I'll try to desribe the proper way to rig your "cascading" downhaul, without writing a book.

From your first picture. There are three small blocks and two lance cleats you need to get into the mix. The complete system will have involve three seperate lines, one continuos from side to side and two shorter lines at the mast. You should have two single blocks with a line tail attached to each no more than a couple of feet long. These blocks should be about the same diameter as that cheek block bolted to the mast below the boom. First remove the continuos long line you have threaded through the swiveling exit blocks and double block on the sail and set aside. Now, take the end of each line and thread (from back to front) through stationary double block attached to the Main sail. Then feed these ends down through the lance cleat located aft of your swivel blocks. At this point adjust the line length in the cleat so each block is hanging off that double block midway between the sail and top of the boom. Now take the long line and, as before thread into the exit block, up and through the "hanging" block on this side, down through the rotator arm, around the cheek block at the bottom of the mast, back up through the rotator arm and hanging block on the other side and down and out the exit cam on the opposite side.

I'm sure someone will have more comments.