You can remove the rust by dipping it n "EvapoRust" for about 12 hours (the time will vary depending on the temperature and the amount of rust). The stuff is amazing; it will remove the rust and not touch the paint. I had a '50 Ford grille that looked OK from the out side, but was rusted on the inside. I soaked it in "EvapoRust" and it cleaned up really well. The original black paint in the grooves in the grille extensions (parking light units) was not touched. It's a little expensive ($80 for 5 gallons), but the stuff is really useful for lots of purposes. It is one product that does what it says.
It works by an ion exchange process called "chellation". It is not a solvent or and acid, so it won't hurt anything. I recently did a pair of Corvette seat belts and it removed all the rust and didn't affect the webbing at all. Try it on something else (an old rusty tool, etc.) first, and prepare to be amazed. You can also get a gallon from Amazon for about $30 with shipping.