Thanks for the response. Much appreciated. I should have been more specific. I'm wondering about the 'cardboard' package-tray/shelf itself. My original is in pretty good condition and I feel I'd be sacrilege to paint it. I was wondering what folks have used to clean/preserve/restore the outer cardboard material.
I bought new. I think a mild cleaner on a rag would be best to clean it. Nothing too harsh as it would possibly damage the coating. I would test it on a less conspicuous area first to confirm it doesn't damage anything.
It also wouldn't hurt to start a thread asking this question as I'm sure there's lot on here with much more knowledge than me on how to clean this without damaging it.