I blast them in my cabinet, blow them off really good and paint with aluminum paint. (no primer).
I've been using the Duplicolor engine enamel with ceramic. Even though these parts aren't subject to heat, I have found this paint to be a better quality than others for stuff like this.
If you want the parts to look a little more original, barely hit it with a scotchbrite or 1000 sandpaper. Makes it hard to tell the difference when comparing to a zinc plated part.
Just did my original hood hinges that way but I didn't scuff them:
