A few years ago, I used a recipe from someone on this board, and it worked fairly well. If I remember right, it was 50_50 white vinegar and distilled water. Use a sponge and wipe it on. Make sure that the combine is clean and dry, and stay out of the sun. Start from the bottom, so that you don't have streaks from the solution running down on the discolored area. Try a small area first, but I think it worked pretty good.... Irv