Drop the bolts in a plastic container and spray them with oven cleaner- - - -the paint will lift off in record time! Rinse them in very hot water and the metal will come out clean and new-looking, with no damage to the threads. If necessary, a quick buff-up with a wire wheel on a bench grinder will complete the job.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!