I use the Scotchbrite Roloc discs as well. Big time and work saver. How rough the surface ends up depends on the grade of pad you use. The super fine gray ones get it to the point where I can start buffing usually. A little sanding may be required in the nooks and crannies the pads won't get into.
The fine (blue) pad is good for removing heavy corrosion. The medium (maroon) pad will remove deep scratches and gouges but must be used carefully as it knocks a lot of aluminum off. Sanding out deep scratches was always such a chore. I see many on here don't bother but I can't say I'm very impressed with their finished covers. Their covers may shine but they still have a big scratch in them, lol.
The fine (blue) pad is good for removing heavy corrosion. The medium (maroon) pad will remove deep scratches and gouges but must be used carefully as it knocks a lot of aluminum off. Sanding out deep scratches was always such a chore. I see many on here don't bother but I can't say I'm very impressed with their finished covers. Their covers may shine but they still have a big scratch in them, lol.