Vintage Black Button Up Blouse with Sequins

Vintage Black Button Up Blouse with Sequins. Unsure of brand and size, the tag is worn out. My guess is it's a small . If you have further questions please message me. All of the measurements will be held in the description. Laying Flat Measurements- Armpit to Armpit- 15'' Sleeve Length- 21'' Length Down from Collar- 18'' V-Neck Length- 7''