vintage Lanvin Boutique Paris France pencil skirt

elegant cloud soft black straight skirt from Lanvin Boutique Paris. no fabric tag but feels like cashmere. Would bet it’s pure cashmere but again no tag. fully lined. zippers on side with top button. Chip to top button. fully lined. no size tag. from top of waistband to hem is 23 1/2", waist is 14 1/2" across lying flat. hips are 19 1/4" across lying flat,