It would be neat to have outdoor lighting fixtures inside our store since our market's lifestyle centers around outdoors in the evening and night. This would add to the atmospherics to the store because it would truly represent an outside urban area.
scrub with a brush and hot soapy water then dry overnight. Use 60-80 grit sand paper ALL over to remove rust, bumps and dents. Make sure to wipe off dust from sanding really well. "open" vent and lay on cardboard outside. Spray with rustoleum "hammered" look spray paint. Let dry for 3-4 hours then flip and spray underside.