There is an Airstream dealer in Baton Rouge, but I have not heard many good reviews on their service department. I take my Airstream to Foley even though it's farther away. But I don't know if even Foley can handle the kind of work you need.
I feel your pain. I know some folks not far from you, in Maurepas, my goddaughter's family. And the cat I adopted last year came from French Settlement, one of a litter of five kittens that were rendered homeless by the flooding. I saw for myself the devastation left behind by that flooding.
Mold remediation on an Airstream would be an expensive and time consuming process. Like doing a shell-off restoration while wearing a respirator to avoid breathing in anything that will kill you. Inhaling black mold spores will give you something very similar to Legionnaire's Disease. One person I knew from work died exactly that way after Hurricane Katrina, while removing water-damaged sheet-rock from his home, not knowing that he was knocking mold spores off the wallboard and into the air in the process.
But before you go to the time and expense of a shell-off mold remeidiation, try these exploratory procedures to see if mold is present in the first place…
Buy at least one of these kits, and use it according to instructions:
https://www.amazon.com/dp/B000HYN1DW...&ref=bit_pcomp
The easiest way to tell if mold is present between the walls is to remove a small section of internal wall (wearing a properly-fitted respirator, just in case. A paper dust mask or a surgical mask is no substitute for a respirator). Then you can examine the inside of the section you removed, and the insulation behind it, and the inside of the outer wall behind that. Use the test kit above to test for mold in every area you opened up.
Do that in two or three places around the trailer. Also check the belly pan. Open every cabinet door and remove drawers to check inside the void space behind them. Also look inside your outer storage compartments. Remove a roof vent so that you can access the space between the inner and outer roof panels through the gaps where the vent trip pieces were.
Figure that every piece of padded upholstery is compromised because it all soaked straight through and may have mold inside. Remove and discard, if you haven't already. No need to test those.
Also, since the trailer was basically fully submerged, you have to figure your entire plumbing system is compromised because floodwaters would have come in through your tank vents. Plan on winterizing (to dry it completely) and disinfecting (to kill mold) and flushing (to remove mold) at least twice before you use it. Getting up top and spraying chlorinated water down your vents while you're disinfecting might be a good idea to make sure no mold is growing in the vents.
After all this time, it's probably safe to assume that your electrical system has dried out. But check as many accessible connections as you can to ensure submersion hasn't damaged them.