Vertical is always best

I started knitting (50 st cast on) at the brownish stripe at the right side of back and knitted until the back was able to reach from shoulder bone to shoulder bone with a tiny bit of stretch. The bottom border is 7 sts of seed st; the basic pattern is k3 rows, p 1 row. I alternated using two skeins of Iro in order to avoid larger areas of dark patches.

I determined how wide to make the shoulders by trying it on. Then I decreased about 2 inches at one time followed by decreasing one st every 2 rows 4 times in order to make the neckline. I just kept trying it on to make sure it fit.
I ended each front with 8 rows of seed stitch to mock the bottom border.
My adaptation to accommodate the "girls" was to add 4 stitches to the length of the front. This was the only way I could think of to create the effect of a short row in sideways knitting.

I used most of 4 skeins of Iro. I knit the body on a size 11 which kept the fabric from being too firm and then switched to a size 10 for the 8 rows of seed st in front. I sewed the shoulders using mattress st. I left the neck as it was. The chain selvedge I knit there was sufficient finishing. I did crochet crab st around the armholes, mostly to prevent them from stretching.

It was quick and I do like it. I will block it and stretch it just a bit lengthwise.