Let’s draft together the pattern of this vintage top.
Start from a fitted basic block with darts.
On back, draw the straight low neckline, the upper one and cut through the waist line so you’ll be able to close the dart.
On full front, draw the asymmetrical neckline and armhole, cut through the waist line, close the darts opening the bust ones at the shoulder.
This is the manipulation of closing the darts.
Attach the back neackline band to the front on the shoulder line.
Draw a slash line on the opposite side to manipulate the dart and cut it.
Redraw both pieces marking the pleats on back neckline.
This is the finished pattern!