As far as I know, all of those ring neck 7ups come from Bryan-Nims in Alabama and Georgia. The example I have actually has four cities listed on the back: Fitzgerald, GA, Macon, GA, Montgomery, AL, and Albany, GA.
It's definitely not an easy bottle to find, although I do see a few come up for sale every year on eBay. You did really well for $5 though! I'd say it's worth somewhere in the $75 range, give or take a little bit. Really nice bottle!