How Do I Restore This Buffalo That I Found? (1927 Nickel)

I found a 1927 Buffalo nickel in my Loomis box today. However, it is completely covered by this black stuff. I don't know if it's some kind of dried industrial oil or tar, or maybe it's been through a fire. You can see the black coating chipping away in a few places, but the vast majority of the coin is covered, unfortunately. I guess my question is how do I restore this coin? Would soaking it in acetone help? I know 1927 is not a key date, and I couldn't tell if there's a mint mark, although it looks like there might be one (or it could just be damage). So if I were to try to conserve it, it wouldn't be for the value. I've never conserved a coin before, so I thought it might be interesting to try on a fairly common coin that's already in pretty rough shape.

Any insight would be appreciated. Here are a couple of images. Thanks in advance.

*** Edited by Staff to Add Year / Mintmark / Denomination to Title. It's very important to have in the title. ***