Cost to refinish - Hemi Valve Covers ???
Stick them in an oven at 200 degrees. Take them out and paint them VHT wrinkle paint. put back in oven for an hour. Will look great and uniform. Finish will be way more durable than air dried paint and getting close to powder coat durablity. I can file my fingernail on mine.
Prep before hand by glass beading, paint remover, and sanding.
This was done just with a VHT wrinke out of a spray can. Very very uniform.