Thanks for the response TC. Just a few weeks ago it was pretty small, about the size of a pencil eraser. I'm guessing that the heat of the summer has something to do with it expanding. It's probably about 2" now. The paint seems pretty thick, and may be easy to work with regarding superglue or something similar. The PO said that it was hit with over 15 coats of paint, and I believe him.
My primary concern with squeezing a substance like superglue under the paint, is that it may cause some adverse chemical reaction. Regardless, I feel that it's just going to get worse if I don't do something.
Thanks for the syringe suggestion, I found one here:
http://www.smartpakequine.com/productclass.aspx?productclassid=1525. I'll do an injection and try to even it out with a credit card wrapped in a chamois.
The paint is way too pretty to go over just because of this. This "blemish" is really annoying to look at. Kind of like a beautiful woman with a black eye. I'll take a cosmetic problem over an engine problem anytime though.
No flaw that I could detect by the gas cap, although it's pretty close to it. I always use a bandana when filling up for just that reason. Thanks again.