![Civil war navy button](https://cdn1.cdnme.se/5447227/9-3/screenshot_5_64e62947ddf2b306ca76f796.jpg)
![civil war navy button civil war navy button](https://dygtyjqp7pi0m.cloudfront.net/i/12003/12106240_1.jpg)
I don't have access to my button books right now, though I believe someone else here has the 'Big Book of Buttons', and it has a section that may show the button. The button at lower right is likely older, a bit different in design, construction, and backmark - can you get a good image of the marks? The darkened/blackened 'bronze' color is original, they're in good condition, I'd leave them alone.
![Civil war navy button](https://cdn1.cdnme.se/5447227/9-3/screenshot_5_64e62947ddf2b306ca76f796.jpg)