This shirt is an Extra-Large 100% cotton polo "On Tour" made in Myanmar by Port Authority. Photos came out bright but the color is a light Olive Drab. Embroidered logo. I doubt anyone ever wore it, looks nice. Might be a few years newer than the category estimate but can't be too far off. Not one that is easy to find and retail at the base exchanges is usually twice this or more.
 

Shipping packaging is no-frills, brown paper or similar, nothing will get hurt and it will save you on the postage.