1. I guess it had rollers on the back to guide the line and a cleat at the front. Similar to this one but not exactly

About the line at the front beam, attach the hook at the center to the bar at the base of the mast, with the little hole, and you have a mast rotator. I think that was the idea.
2. For the jib sheet, one each side, 2:1: start from the block, go through another simple block attached to the jib clew, back the the first block, trough the cam and to your hand. (and back to the other side block and tho the clew.

3. You really need the hook and the ring on the halyard, forget the idea of not having it..