My son and I are still learning. We've seen several posts and articles that say do not clean coins, especially older ones. This 1943 D dime is so discolored it was a challenge to read the date. It doesn't seem "dirty", instead it appears to have been in a fire. We think the date and other detail would be considerably more legible if something was done to help it. In this condition, we have no clue if it has any value above its silver content and we don't know whether we should keep it, sell it, or just put it aside until or unless we can find another one in better condition. Help?