As an incentive for someone to buy them, maybe add some bondo (for
filling the holes) to the offer.

Option 2 (expensive?): Have them sand blasted, bondo the holes, prime
(with metal primer) and repaint. Spray primer and spray paint in
aerosol cans. If funds are limited, do just a few at a time. Start
with the ones that are damaged the most, if you screw up with the
damaged ones, pfftt, they were in bad shape anyway.

Option 3 (more expensive): Have them sand blasted, bondo the holes,
have them powder coated.

Compare those options vs selling and buying new.

If you're thinking spot repairs, maybe invest in a grinding wheel,
with a wire brush wheel, to buff (rather than sand) the rust spots.

Sonny