True Vintage Black & White Mod Dress

I purchased this little number from a vintage clothing store in New Orleans in 2015. I wore it many times, but since then, it's been hanging in my closet. black and white. no material tags, brand, or size tags but I'm sure it's polyester. back zip. hook and eye closure. eye part is simple thread. fabric has some stretch. it appears to have been shortened and re-hemmed. I've repaired the part of the hem that was falling down. dress has been recently washed and air dried. I'm listing this as a S. measures: 34" long 17" pit to pit (flat. darting at bust gives a form-fitting fit) 13" waist (flat) waistband starts 14" from shoulder skirt is 19" long sleeves are 21" long from shoulder