Your front window had grey weatherstripping, also known as a "window glazing bead." Airstream Dreams sells a replacement, using the original manufacturer's die and the same material. They even have a diagram of the original window assembly at their website:
Look under "Gaskets," and the year of your trailer.
I agree that the rockguard was probably moved--very unlikely that Airstream would have let it out of the factory with a covered up nameplate.