My experimental project has an O-320 that has been sitting for many years. My magneto drive gears (steel ones) have some light rust on them and I assume the other accessory gears probably have some surface rust also. My Lycoming overhaul manual isn't really clear on removing rust off gears, it does say to NOT media blast any "machined surface" (don't know if a gear is considered a machined surface). Is my best bet just to use scotchbrite? Any experienced advice out there on the subject?