I swatched this yarn (which is a felted singles that’s somewhat thick-and-thin) and found that the gauge on 3.75 mm needles was better than on 4 mm ones — just a little more substantial, which I think is going to be better for the potential wear issues you get with a singles yarn/short-staple fibres. My stitch gauge is close enough that I’m confident it will fit; the row gauge is off, but I have to adjust for my tall father anyway, and I have lots more yarn than I’ll need.

I’m going to incorporate the cable from the Howth vest, just in a vertical stripe up one side of the vest. (Dad likes the look of that vest, but project notes indicate that there are issues with the pattern, so I’m going to side-step that and go with a pattern that gets much better reviews.) I’ll work the front with 4 extra sts to accommodate the cabling.

Size-wise, Dad has a 46” chest but only a 40” waist, so I’m going to make a straight 46” vest — I know that the pattern recommends some positive ease, but I also think that the knitting will accommodate the wider part of his chest without being too tent-like over the rest of his torso. Fingers crossed! I might work the back at the straight 46” size and the front with a few extra sts (beyond what’s needed for the cables) — that was the technique used in the CustomFit sweaters I’ve made, and it seems to do well at keeping the seams straight at the sides of the body, without making the math much more complex.