This could also be created by repurposing an old sweater. scandi chic couture fashion gilet top en trend style for 2015
i think you could make this with tunisian. when it gets the the split, you could keep working half the stitches until both halves are long enough and then start stitching across the entire piece again at the other end.
Falling Water Vest pattern from Yarn Barn (or Rav). Want to make something similar on the KM with a lighter yarn for spring layering.