GL & John - just wanted to wrap this thread up.
Took #2444 to a local boat yard (next town over from me), they service small sail boats, it is the "go to place" for repairs by folks at my sailing club, and they also still that make new Cat sail boats. Met with one of their riggers, he was familiar with DS, said he has worked on them, and we talked about adding a spinnaker set up. He looked at the mast, "restoration" work that had been done, and he thought it all looked fine.
He thought the best place was to add a third exit sheave was at the bottom of the mast, near the existing main & jib exit, then back up to the deck.
GreenLake wrote:There seems space for a third exit sheave - there's that flat spot that extends above the other two. Perhaps all it takes is to cut a slot and add one.
He will also get back to me with his thoughts on adding a third cam cleat on deck top for the spinnaker, or look for a another solution, e.g., 3 line clutch to mange all three halyards... was leaning toward 3 line clutch as it would be simpler.
He liked the idea of lashing 40mm blocks to the existing aft horn cleats and liked the picture I had posted of a friends DS front block set up, basically a cheek block, cam cleat and the fairlead with the rubber piece so the guy line can slip into the fairlead. We talked about having a small ratchet block forward (Ronstan Orbit 40) but he thought that was not necessary "simple solutions are good on DS". He was not concerned about accidental cleating on the cam cleat.
He is going to get back to me before he worked on the boat this winter to talk about downhaul and topping lift set up, spinnaker halyard, shackles, other hardware needed.
GL - he too thought that the size of the 4:1 Vang / line was fine and I'll figure out a cascade system myself to add in the spring when I get the boat back.
Left #2444 at their yard to be stored, they got it covered before the Nor'easter hit here the next day. The other DS in my driveway got shrink wrapped also before the storm. We are not on Cape Cod for the winter, so it was great getting boats put away for the winter and knowing that I'll be sailing in the spring.
Thank you all for good thoughts on spinnaker rigging. Very helpful, I learned a lot.