Unisex satiny button-down shirt

Measurements (taken flat): Pit to pit — 23 in Hips — 22.75 in Sleeve length — 22 in Cuff width — 4.6 in Length (collar to hem) - approx. 30 in There is no size, material or care tag, but the fabric seems to be satin. Also, the shirt has been washed, but there are still some stains on the outside and inside of the shirt (see photos).