I just imported a Skybolt from Canada and needed to remove / cover the 18 inch registration numbers under the left wing. I ended up wet sanding the edges to feather the paint. I repainted the left bottom wing panel to cover the dark blue letters. Then I layed out the checkerboard pattern. I cheated a little bit by masking off the grid with 1/16 fineline tape and masking off the squares that should stay white. This means the corners of the red squared don't actually touch. When finished it is barely noticeable. Here are some pictures.