The thwart sounds like a very early-70s cleat location. And not a good one! You have at least one on the top of the centreboard case with an aft lead block, which is a good way to lead most of the controls.Mostly, I used the MacKay layout to get a sense for things. When it came to me, a lot of the control were on the thwart. I have almost all of them running back now, but I still need to do some work to run the vang back properly.
You're on the right track - since the late 1970s, no one has cleated the centreboard. A continuous "friction" system is standard, with connected up- and downhauls and an elastic to take the slack off. It's simplest to run it just along the case, although it can be led to the side decks. (Most top racers today actually use two separate lines because (I assume) they want different purchase ratios for uphaul and downhaul. The more complicated the better I guess )One question that I did have is how to run the centerboard. The continuous vang and cunningham make sense to me, but I am not sure what makes sense as far as cleating the centerboard. Do you just have the centerboard stay in place with friction? Otherwise, it isn't clear to me how I raise and lower the board from either side easily.
It's not a problem unless you want to change to a swiveling cleat.the main mainsheet cleat is on the floor of the cockpit rather than on the aft end of the centerboard trunk. I was trying to think if there was a way to extend the trunk aft, but for now I am just leaving it where it is as it isn't the biggest deal ever.