You might want to try Eazy-Off oven cleaner. Its used on fiberglass boats all the time to remove lettering, etc. and doesnt hurt the fiberglass beneath. Put the mix of EazyOff on the surface, add a bit of water, cover with saran wrap, wait for the paint to lift. Sand away the remaining paint shadows with 1300 or 2000 grit wet and dry paper. I'd test such a method first to be sure that there is no chem reaction with the flare. Most polymers are chemically compatible with inorganic solvents: caustics, acids,etc. but will readily dissolve/soften in organic solvents found in paint strippers: MEK, Ethylene Chloride, etc.
Alternate: Remove the flare and immerse in warm water. A long term soak in warm water will "lift" the paint from the surface. Problem is that it will take up to a few weeks for the paint to release.