For identification without damage I would soak it in motor oil for a day. Then scrub with a nylon brush. Dirt and rust will be loosened without further damage. Then rinse with mineral spirits, oil lightly with gun oil to prevent further damage. If scrubbing reveals pitting it is likely a total loss unless it was a famous persons gun and that would have to be verified for any value to be assessed. Fun to look into though. If you can, post pictures.
You can't fix stupid....however ignorance can be cured through education!