Harley Davidson Vintage Men's Med. Founders Black Grey Button Down Shirt

Left Front Breast Pocket Meant to be untucked has tails and slits see pics P2P 20.5” Length 31” Excellent condition Vintage Harley-Davidson Founders Short Sleeve Button Down Shirt Size Medium - late 90s. Tagged a size medium but being vintage and based on measurements I am saying a mens small? Could be unisex as well, very lightweight and flowy. Perfect for summer. See measurement dimensions in pictures for approximate sizing comparison.