Vintage Popover Shirt

Sturdy vintage cotton pullover shirt (tunic style) in light blue. I believe this shirt was some sort of foreign uniform or off hours military clothing. “Size 39” roughly equates to a medium. 21” across chest pit to pit. 28” long from tip of shoulder. Sleeve length 24” from shoulder. Two very small flaws in fabric (see photos) that are consistent with age of vintage garment.