The skirt is worked in one piece to armholes. The body is then worked for about an inch at which point the sleeves are joined and the yoke is worked in one piece until finished.
There are a few short rows around the body to raise the back/side neckline.

Requires 4 buttons

Errata: at the neckline change to UK12 I.e. 2.75mm needles.
Buttonholes are unevenly spaced in the pattern. So where it says to work 11 rows in garter just do 9 then a buttonhole row, then another row, you will then be ready for the decrease row. The next buttonhole needs to be worked sooner than in pattern to match spacing of 5 garter ridges too. The same number of rows are worked overall.