Vintage NWT deadstock 70s smocking detail top M

Vintage NWT deadstock 70s Devon top. Cute rainbow smocking are shoulders, collared neckline, puffed elastic cuff sleeves. Would look amazing with high waisted jeans. Has the ILGWU tag. Marked a medium but looks to be oversized, so would likely work for a large too. Has a small mark, seen in pics, may come out when washed. Measures (flat, unstretched, approximate): armpit to armpit: 20in, waist: 20in, hip: 20in, shoulder to hem: 25in, sleeve: 13in