I don't know about the emblem below the window, but if your car is a true SS396 then you have gotten yourself a very nice piece of history. They aren't as rare as the hope diamond, but they are very desirable. Congrats on the car. Ones in really good shape will fetch a good price, but it all depends on the buyer. I've seen good condition cars go for $25,000+ at certain shows. Get a classic car trader magazine, or a price guide. You can get a good idea by looking at what others are selling theirs for.