Jim, I removed all numbers and decals from my 1971 Tradewind a year ago, and the ghosts won't leave the surface, not even in the California sun. You can still make out Wally's mugshot on the WBCCI sticker, it's etched in the Aluminum, seemingly for good. My next resort will be wet sanding and polishing. Wish me luck! Uwe Salwender Orange CA