Swatch 4 - K1P1 ribbing (with a seam)....again. This time I'm much happier with the result. Although it might look like it's half a stitch off in places, the seam is done bar-for-bar correctly with no fudging to make the ends match.
I found I got the best results by having a knit stitch at each selvedge to be seamed. I knit the strip on the right ending with a k2 to accomplish this and still keep the k1p1 pattern intact across the seam. I'm going to hand this one in, but before I use the seam in an actual garment I would like to do some further experimenting to see if it would work with a tubular cast on and bind off.
Who am I kidding? In actual "real life" knitting (unless there was a really good reason for a seam) I would most likely convert the pattern to knitting the garment in one piece to avoid the seam altogether!