Welcome to the forum:
In order to properly serve you it would be helpful if you included year, model and trim level of your Airstream. While tambour has been prevalent across the many years Airstreams have been produced, I'm sure there have been many different ways it has been installed.
As for my tambour in my 310 I removed the track with the tambour still in place, light scuff with an abrasive pad (fine), clean with a good cleaner like Spray Nine, masked off the track and handle and then spray painted the tambour that would show with the door closed.
Per Mare, Per Terram and may all your campaigns be successful.
“It’s a recession when your neighbor loses his job; it’s a depression when you lose your own.” "Harry S Truman"