Vintage Handmade Asian Style Maxi Dress with Sash

Vintage dress with an Oriental style, likely handmade. Shell print fabric on top and floral print on black (likely silk) on the bottom. Also has a wide sash in the same fabric as the floral print. Small belt to cinch it tighter at the waist. Collared V neck and half sleeve. Looser fit with a slight flare towards the bottom hem. I don't know how the sash is meant to be worn, perhaps bound at the waist in a kimono style? Pit to pit: 17.5" when lying flat (approx 35" circumference) Collar to hem: 47.5" Sleeves 14.5" from where they attach to the shoulder of the dress. There is a small stain on the front of the dress near the midriff, I have not tried to remove it.