Adding in my notes which I had saved to my pattern copy.

Using 4mm needle that’s 23 sts per 4 inches when I’m supposed to get 22.

Colorwork is 5.75 sts per inch
Plain is 5.25sts per inch

Going to make the largest size.
Use 4mm on color work
6 sts per inch
6rows per inch

3.5mm on plain, gauge is:
6sts per inch
8rows per inch

2.75 for ribbing

Need extra stitches for underarm at least an inch which is 5.75 stitches. Therefore cast on one extra repeat.

25+8=33 sts at underarm