I deal with rusty bright work all the time when I restore bikes for the bike exchange. My first step is to remove everything small enough to fit in a quart plastic freezer bag and immerse it in a large open mouth container half filled with white vinegar. I fill the bag with vinegar and drop it into the larger container . this makes retrieving everything later easier. then I put larger items like center pull brakes and the front derailleur in with them and let everything sit overnight. The rear derailleur goes in another container filled with mineral spirits. The next day I remove the bag and empty the vinegar back into the container then take the bag into the bathroom and fill with water to rinse, dump out the water, and take back to the shop where I set everything on clean paper towels. Next I will use brass or steel wire brushes to brush off the rust that the vinegar has loosened. finally, I will buff on a buffing wheel attached to a bench grinder. Often I will use a wire end brush chucked into my bench model drill press to remove rust from small parts. It doesn't seem to harm the finish and works on chrome and aluminum parts. It is also handy to clean the threads on bolts and remove crusted grease from the teeth of chainrings. In fact, I seem to find new things to use it on almost daily. For removing heavy scale I will sometimes use a cheap retractable blade box cutter laid flat on the surface to scrape it off , being careful to keep the blade flat to avoid gouging paint. another thing to keep around is Brasso , which works well as a metal cleaner, as well as Dupont No. 7 white polishing compound, which I use to deep clean the painted surfaces of scuffs and dirt that gets embedded in the paint.