Right, now I know why knitters don't finish off necklines with cables. When I finished Jack's pullover, I thought the cable finish looked good. But it stretched, so the pullover looked saggy and horrible. Not a good look. I did mean to correct it in the middle of summer, when the pullover was languishing in the cupboard, but of course I didn't get around to it until the weather turned cool and winter was definitely on its way. I used a circular needle to pick up stitches around the neck and work a more conventional ribbed neckline, without undoing the cables or anything else. It has worked fine and the pullover looks a whole lot better.