The best thing you can do to document it, is to take the actual overlay off the panel and scan it into the computer with a high res scanner. Even in pieces if you have to.
Other than that, take SEVERAL high res photo's of the overlay with the camera lens directly perpendicular to it. Like perhaps taking 5 or 6 pictures of it from left to right.
Also when taking the pictures, its ALWAYS better to ZOOM in, instead of just moving the camera closer. Cause then you avoid any fish-eye effects.
The point of all these high res pictures are so that someone can vectorize the art...
