I would have posted this sooner, only my first attempt at this Ziggy Zag sweater was too short in the body. Luckily it is knitted top-down, on circular needles, so it was a relatively easy fix: insert lifeline before start of ribbing using tapestry needle, rip back to lifeline, knit an extra inch in stocking-stitch, repeat the 3-st twisted rib for 2 ins, cast off.
The error could have arisen in my gauge (although I did swatch, and it was dead on). The schematic shows the yoke for this size at 4.5 ins, when I measured it on my completed, too-short version, the yoke was only 3.5 ins. So 7 ins of stocking stitch, rather than the stated 6 ins, was necessary to end up with a sweater of the correct length.
Notwithstanding the re-knitting, I love the little baby sweater, and hope Gabriel (and Gabriel's mum) do too.
The pattern is by Carol Feller at stolenstitches.com. The zig-zags that give the pattern its name are in the yoke, shown in more definition below: