Airstream Dreams does not have the proper window and door gaskets. Those are Airstream items, and since they are not a dealer, they cannot purchase anything from Airstream, except at retail.
Check their web catalog.
They also are unlicensed to sell one of the items that they do list, but according to Airstream, that won't last much longer.
Airstream has had a long standing policy, that if you copy any of their logo's, nameplates, etc., you must be licensed. They reserve that for a dealer, or for someone that manufactures like items, such as a clothing manufacturer on a daily basis, as opposed to having a few made.