Vintage purple blouse unique large flutter shoulder asymmetrical button down med

So fun and one of a kind! My guess is this is from the 80's. Buttons down on left side. Double layer to funky shoulder design. Small amount of wear & loose threads but overall in good condition. No size or fabric tag. Fabric feels like a lightweight polyester blend. I'd say this is a medium/large- see measurements: 21" armpit to armpit 24" long