Civil War Era Union Officers belt buckle and belt

This appears to be a custom all leather belt with a Civil War union officers belt buckle. This was my Uncles so I'm not sure if it's authentic or not. Non-adjustable. Approximately 50 inch waist. Looks like a copper like 2 part Buckle that says e-pluribus Unum on it with silver wings. In very good overall preowned condition. Buckle and ends may need cleaning. Nice thick substantial belt. May have been used for cowboy shoots by my uncle or reenactments. Offers welcome.