Dutchman or sail loft
When we bought our 1987 h40 in 1997 it had fabric Dutchman Control lines. When we replaced the main and got new Dutchman components in 1998, they came with monofiliment line. We got replacement lines from the Dutchman exhibit at the Annapolis boat show. Your local sail loft ought to be able to steer you to Dutchman directly.I suspect you could also buy real high strength mono-filiment fishing line or line for a string trimmer.BTW, when we got the new sail we went from two to three control lines. Our 400+ sq ft sail flakes a lot better with three lines.To install we drop the topping lift, resting the boom on the cabin top. All we need is a #2 Phillips drive screwdriver to open the clamps that hold the crotrol lines to the topping lift. Simply tie an overhand knot in the control line. The knot fits inside the clamp.