Now you have some time to look over that checklist and ask questions about it on the forum before you look at a trailer.
I was pretty ignorant of how trailers, and especially Airstreams, work. We knew that between the two of us, there isn't much we can't fix. But that list would have been Greek to me.
We have put in new axles, repaired, replaced or removed many of the plumbing, electrical and appliance systems and replaced some of the floor and all of the interior walls and cabinet panels. We now know a lot more than we did. I might possibly have been a bit less eager to buy a "fixer-upper" if I had known fully what we were getting ourselves in for. But the work has never kept us from camping and it's been a satisfying process.
Long story short, any "issues" a trailer might have are as much about the buyers as about the trailer itself. If you aren't at least somewhat handy in the fixit department, it's best to steer clear of a vintage trailer. Floor rot is a potential problem in any older trailer. Know what to look for and what a repair would entail. Talk the price down accordingly.