Cutting paint

[simonh]

Some cheap lacquers don't have much uv protection so the basecoat underneath can still fade. If any repairs have been done in the past there's a good chance the colour has had to be blended and the repaired panels and possibly the ones either side will have been clearcoated. Unfortunately if this is the case no amount of buffing will get rid of it.

Even just use a bit of your compound on a clean cloth and buff a small section by hand to check. If it stays basically white then it's clearcoated, if it goes pinkish red then you just need loads of elbow grease!