Firrst, $800 would not have repaired the separation correctly. Our trailer had a simiklar "hack job" done on it before we bought it.
Second, almost every warranty fo any dealer or repair shop is from 90 days to maybe one year from date of repair. AFTER TWO YEARS, I'm pretty sure there wouldn't be any warranty, even if the dealer was still in business.
So,, if you don't want to tackle the job yourself, which would involve removing almost everything in the bathroom and replacing the entire floor back there, you should look for an Airstream dealer with a good reputation in their service department, or make an appointment with the mother ship. Jackson Center usually has a special for Wintertime repairs, give them a call if you can't find a dealer to take care of it.