Actually they stared out black, went over them with the belt sander first to smooth the casting then the random orbital with a 120 pad. And yes I used compound sticks, settled on just tripoli and white rouge, the black emery really isn't needed on aluminum. Started out using a hand drill then I thought to myself "dummy you HAVE a drill press!"
Funny thing about stripping the paint, I used orange stripper and let all the pieces sit overnight, the paint on the clutch and sprocket cover just fell off when I rinsed them under some water but the stripper didn't even touch the paint on the mag cover and I ended up having to sand it off.