Wacky backstay
I don't think that the 23 ever came with an adjustable backstay. On my '79 and on every other 23 I have seen, the backstay arrangement is this wacky 2"x2"x2" triangular plate with a hole in each corner; one hole is attached to a foot long strand of wire rigging which attaches to a chainplate at the transom. One hole attaches to the backstay via a turnbuckle. The mainsheet attaches to the third hole. In essence, the backstay is interrupted about a foot and a half short of the transom so that the mainsheet can be attached to it. I don't know how you could make this system adjustable; every time you relaxed the tension on the backstay, the mainsheet attachement point would sag lower. If you do have an adjustable backstay, it is most likely an owner-added feature.
