So maybe I do not know what the hell I am talking about because I am a new guy - But I put my 1858 seated half (that I found a couple weeks ago) in some lemon juice overnight and it came out well. Yes the back looks just as good. But to me, this is as good as a coin can look after being buried all those years. It looks no more worn than the modern change in my pocket. It was halfway under a huge rock which was under a big old tree. Maybe that protected it. But I am proud of this one. And this post is also for anyone considering a relatively safe and effective cleaning method that will not turn your silver coin white or yellow or whatever.
Nice coin new guy, I'm jealous! How long did you let it soak? Better yet, do you have a before picture?