Do you have nail polish remover? Give that coin an overnight soak, it will arrest any further serious corrosion. Pure acetone is the best because it doesn't have the trace chemicals in nail polish remover but on a coin like this I wouldn't be worrying about those too much, just basically keeping the coin stable. Hey, we take them as we find them, we all got coins we wish were in better shape.
Wish I the devil was in better shape........ordered egg plant at the local Chinese restaurant and when I arrived for pickup was told that they were out of egg plant. You couldn't have phoned me back that you were out of product? Drove 4 miles to find out No Dinner? Bloody Hell. Sorry for the rant and drive by shooting. Buy the acetone (pure) at the local Home Depot or hardware store.
And whatever you do, don't put it in a Styrofoam container (found out the hard way). Use an old pickle or relish (glass) jar.
Wow, what bad service. Surprised you didn't twist them into a fortune cookie. Metaphorically-speaking, that is to say.
How frustrating! You're welcome to rant anytime as long as you keep posting those great music videos! LOL Sorry to hear about your dinner though...how frustrating! I will most definitely not use a styrofoam cup. Thanks for the warning!