Motorcycle Repair: 78 Honda 750k, urethane paint, dark blotches

Question
I would like to polish the dull engine. I've been told that the casing has a coating on it, there are dark blotches under this coating, which makes the engine look dull, old. I've seen pictures of the same bike, restored to a shine. Can I use elbow grease, or is this a job for pros? How do they polish the castings?

Answer
Sorry, for taking so long to get to this answer, but I've been out of town.

Dan, the cases are painted with aluminum paint and the side covers are covered with urethane paint.  You can strip the paint a coatings and polish the cases.  It will take a lot of work but it can be done.  

Regards
Rich