The "guts" were an option for the boat, there should be serial numbers on both tubes, parts are still available. There's also a long, hand etched number on the underneath side of the boom, near the mast
Pushing down, or forward seems normal to me, to go into FWD. Most all Hunter boats have LH props, but back in the day there were some Righties. Is the boat out of the water?
Sta-Set X is really wiry, I personally don't like it, too stiff and hard to work with. Samson MLX3 is a reasonably priced Dyneema performance line, 10mm, sold by the foot, haha, only in the USA!