Chocolates vintage blazer, size S

80s vintage black blazer with shoulder pad and 4 fancy buttons (buttons are a bit loose) no damage, no stains purchased in local vintage shop, I thought I would lose weight, but it's still too tide on the buttons area. it says size 10, but it is not, it is more like a size 4-6 here is the measurement lay flat and when buttons are on Pit to pit 21inch Waist 16 inch Sleeve length 24inch