I go with dry sanding, alt cover is the hardest to do though and depending on the condition you could be there all day. On my basket case the alt cover had so many dings, I sanded it first up with 120, I did two long sessions and then just resolved that the dings were too deep.
If you only have a ding here n there start with the white 120 paper and a cork block on it's edge, if you only have light scratches start with 240 or 280, then 600, you can buff from 600 but if you go from 600 to 1000 or 1200 you'll have better shine.
The main thing when buffing is to have your bench grinder or buffer secured to a bench that won't move so you can really push hard on the wheel, do it in short bursts, the motor will slow down, if it doesn't you ain't pushing hard enough, do it in short bursts of about a second at a time, let the motor regain full speed then do it again. Start with the stitched buffer and course compound. Then go with soft leaf buffer and fine, pushing hard with the fine as well. You'll get it looking chrome like. I haven't found any easier way to do it unless you have a linisher to do the sanding.
Here's a rear brake arm I did by hand sanding, started with dremil and then sanding as above. It's made of steel of course which is even harder to do than alloy but this is how it should look. This arm would have taken me a good day's work to do so that'll give you an idea of the commitment required
Of course a Bourbon break here n there helped.
