US WWII USAAF Aviator's Sunglasses & Case, AN-6531, Identified

Original era manufacture. A complete set with green tinted glass lenses with a leather storage case, which is marked on the reverse, Thomas H. Winburn O-401280. See page 271, in Vintage Flying Helmets by Nick Prodger, where he shows a similar pair identified as AN6531 Type II sunglasses. The glasses are sound, displaying typical wear and use. Possibly manufactured by American Optical Company.