A cover would probably be worse. It’d trap moisture and other things against the metal and it’d probably make the issue even worse. It needs an enamel coating or something, but that’d make far too much sense. Alternatively, since it’s bare metal, you could remove any rust that occurs pretty easily, but it wouldn’t look as smooth anymore. They could also possibly cheaply manufacture and sell replacement parts, since it should be (assuming they didn’t do things too dumb, which is a stretch) fairly easy to fabricate.