It's a really nice job that way..
Polishing would be too much for a bike that is gonna be used and not just stay in a showroom for the end of its life..
Actually, if I were you, I wouldn't even thought of sanding the edges of the fins..
A little question..
What did you paint the cases and the cylinders/heads with?
A mechanic I know told me that if you have a primer, or just the old paint of the cases, you can use normal synthetic enamel for the outside of the motor..
2010 Honda XR 250 Tornado