The main halyard is hooked to a sliding eye for storage only.. but that's where you might put one of those blocks, using one of the springs to hold it upright.. although in your earlier pics of hardware I don't see a real, proper genoa car. But in your bag of tricks you may find a single sheave block with a swivel shackle, around which the springs would fit to hold the block upright. Attach that to the sliding eye currently shown with the halyard stowed on it.
The tracks should/would look like this; a more common style of jib/genoa car is the next image
Winches marked 'jib winch?' is your main headsail sheeting winch, usually called the "primary".
The aft facing clutch on the coaming is a bit of a mystery (maybe backstay adjuster? -it looks like you've got a backstay tensioner on the split, but it's not going anywhere) It (the clutch) is facing the wrong way for any jib sheet action.
The winch marked Main sheet winch? would be for the various lines that are supposed to be led aft through the clutches - likely all your halyards and perhaps some reeflines, vang, cunningham etc. Similar setup both sides of the hatch, I imagine.
This boat was obviously well looked after at some point, and pretty well rigged and equipped. You really hit a bit of a gold mine here. I hope you're able to put the big picture together soon.
Here's a shot of our boat, you can't see the jib car lead but you can see the sheet run down towards it, aft to the block on the toerail, and then up to the winch on the coaming.