Yes, the part that attaches to the ceiling (track) is part # 201728-01.
The part that slides into it (trim) is part # 201728-03.
It's priced per foot, but comes in 8' lengths. Your local Airstream dealer can order it for you. If you can get them to bundle it with another shipment they're going to be receiving, you can save yourself shipping costs - which would be far more than the actual trim itself.
How do I know this? I just ordered some through my local dealer.
Welcome to the forum, by the way!