A trip through the media blasting cabinet shows there's still good metal under the Tonka truck bed's layers of rust and paint. The glass bead didn't quite get the job done, but good old silica sand did the trick. The fender I blasted looks brand new.
@casablanca It looks like orange was the original color and the red got sprayed over it at some point. The truck (and a bunch more like it) actually belong to a friend of mine, so the re-assembly and finishing will be his work. I'm just helping out with the media blasting to clean up the old metal.