I sent this to World renowned tintype and Civil War photography expert Rob Gibson, and here is what he had to say about it. Hey Rob, great talking to you today.
From what I can tell the photo is a Union, African American or Native American soldier. Nice bright image with some hand coloring. Judging from the wipe marks I would say the image was unvarnished, and part of the emulsion was wiped away.
If it were varnished, it would appear smeared, but not darkened and scratched. Probably not a lot that can be done it bring the image back.
The item "Civil War Tintype Union Soldier Daguerreotype Case African Native American" is in sale since Saturday, February 25, 2017. This item is in the category "Collectibles\Photographic Images\Vintage & Antique (Pre-1940)\Tintypes". The seller is "rdj000dr" and is located in Jefferson City, Missouri. This item can be shipped to United States, to Canada, to United Kingdom, DK, RO, SK, BG, CZ, FI, HU, LV, LT, MT, EE, to Australia, GR, PT, CY, SI, to Japan, to China, SE, KR, ID, to Taiwan, ZA, TH, to Belgium, to France, to Hong Kong, to Ireland, to Netherlands, PL, to Spain, to Italy, to Germany, to Austria, RU, IL, to Mexico, to New Zealand, PH, SG, to Switzerland, NO, SA, AE, QA, KW, BH, HR, MY, BR, CL, CO, CR, PA, TT, GT, HN, JM.