Thats pretty much it,
Wet & Dry (800 grit to start with then move to 1200 grit) the letters until they are nice and smooth. Additionally we used this set to really polish it up:
http://www.frost.co.uk/item_Detail.a...olishing%20Kit
Richard did the polishing first, then masked the letters and sprayed the cover (a bit of a clean up and treatment with metal ready first before spraying).
After spraying pulled the mask of while it was still wet and used thinners to clean up over spray.
Finally give it a bit of a polish again. We're using Meguires NTX metal polish to keep it nice and shiny
Spraying first then rubbing the paint off will also work