Edited a bit after rethinking some stuff....
Shadow Catcher wrote: .....have a trailer that is superior to what they would provide as a replacement.
Shadow Catcher has a very valid point. I had a good discussion with my dealer, who handles a number of different brands and has been in the business a long time. Our concern about sending my trailer back to the factory was that they'd make more of a mess trying to fix
some of the items I was concerned about. Getting them to build a new one might not yield much better results....south Georgia construction, build 'em fast and cheap.
Our game plan was to be specific in a letter to the dealer, who would send it to the manufacturer, describing the issues. It would be costly to return the trailer to the manufacturer for rebuild, the items to be corrected were far beyond a local dealer's capability. We proposed that I do the corrective work, to my own satisfaction, and be reimbursed something for my labor. Not a lot...maybe $$$$ in my case. This would have been overall cheaper than other corrective possibilities and would have allowed for a somewhat satisfied customer. XXXX went out of business. Ha!
Many manufacturers only paint the wall posts where they are visible after the plywood walls are installed...that's just normal, fool the customer. I'm not sure if you'd have a failure issue in the future though, most of the cargo trailer going down the road are built that way, they fail and get beat up elsewhere. If you don't have a major leakage problem the rust will probably settle down an be a non-issue, especially if taken care of with one of the rust inhibiting products. Of course,
you will know it's there.
If this is going to be a thirty-year-life trailer I would maybe be more concerned...although still aggravated.