John: Assuming you want a polished finish, hand sand down to 600, then buff on a sewn wheel at 1750 with a white compound. check carefully to be sure you get all the scratches, and go back iwith sandpaper until you get them all. Wipe all the compound off the knife before proceeding
Then,, repeat with the same compound on a loose buff, also at 1750. I have also used ZAM from TKS-it works well on plastics.
If you buff a properly prepared surface properly, you only need 1-2 minutes to get it done. I'd suggest contacting RW Wilson-he has boiled the whole compound thing down to just 3 compounds, I believe. I tried the finest two, and they worked just fine. You can go nuts buying wheels and compounds, and, the time you save changing wheels on your machine far exceeds the time you can save by using 8 different specific compounds, when 1 will do. (been there, done that!)
My best advice is to get your wheels mounted right, screw them down hard, and use a wheel rake to thoroughly true your wheels. This makes a tremendous difference in your buffing results-it did for me. When you have the whole perimeter of the buff contacting the wheel equally, you get results FAST.
Good Luck, and WEAR THAT RESPIRATOR and eye protection. I've had 3 surgerys to remove clogged tear ducts (green chrome rouge). When they stick that big Novacaine needle in your cheek, and you pass out because it's so disgusting, it's embarassing!!
RJ Martin