I was going to use this fastening but then I started knitting and forgot. I’m leaving the directions here for future sweaters.
Cast on 59sts.
1st Row: Knit (right side)
2nd Row: K11, yfwd, K1, yfwd, K10, yfwd, K1, yfwd, K16, yfwd, K1, yfwd, K10, yfwd, K1, yfwd, K8.
3rd Row: Knit to last 4sts ,K2tog, yfwd K2(for buttonhole)
4th Row: K12, yfwd, k1, yfwd, k12, yfwd, k1, yfwd, k18, yfwd, k1, yfwd, k12, yfwd, k1, yfwd, k9.
Continue increasing like this to 155sts ending with wrong side row and having made another buttonhole on the penultimate right side row.
Now work as per the pattern from where it says “Lace Portion” but cast off 3sts at buttonhole end row before commencing the lacy pattern. (This makes the top half lap over and the lacy half meet edge to edge).