Keeping dustcover looking new

Thank you all for your responses. Will definitely try the Novus route.

I am guessing to never use an ammonia base product?

I keep mine covered with a micro fiber or silk cloth this way not really any dust to remove. If left exposed I always blow off dust first with keyboard duster. Then use a Flitz micro fiber cloth and spray called Plexus.

NEVER use windex, keep away from direct sunlight and a damp fibercloth with water is all that is needed and as stated above go in one direction when cleaning, never circular. Avoid anything abrasive or chemical. Where there are fingerprint smudges, a mild dish detergent solution with water will be sufficient. Wipe dry with lint free or microfiber cloth.

FWIW, I just ordered a 8oz bottle of Novus #1 cleaner /polish. Will update with results in the future if anyone is interested...