I used the pattern to help me with the basic framework, but modified the body quite a bit.

Dc rows are completed as alternating front and back post stitches for 8 rounds followed by 3 rows of shell pattern.

Shell rows: ch 2, dc in first st, skip 2sts, dc cluster (2dc, ch1, 2dc all in same st), skip 2sts, fpdc, repeat from across, ending with a dc in last st. On reverse (wrong) side, I used bpdc instead of fpdc to keep the “ridge” on the front.

Sleeve: my count was 37 sc at underarm and not 27.
Row 2: sc2tog every 4 sts for a total of 30 sts.
Row 3: sc in all sts around.
Rows 4-16: Hdc in each st around for 13 rounds.

Row 17: sc around
Row 18: slip stitch around, join, fasten off.

I made this as a matching sweater to my little Primavera Skirt.

Sleeves are rolled under a bit for photo with Teddy bear.