The good news is that trailers built in that era were built well, the industry wasn't afraid of throwing some steel into it. As a welder, I'm sure you know what that means.
The chances are that the trailer is full of structural rot. Once there are just a couple leaks and they are left to leak, the wooden frame starts to rot.
You can look through the restoration thread in my signature line, "The Cowboy/Hilton" where I restored a Starcraft in similar condition. I spent around $5K and 6 mos. fixing the Starcraft and upgrading everything but the axles. The Fayatte rims are still sold, try E-Trailer.com. I had serviceable brakes and wheel bearings. I did change out all the brake wiring.
If you have about the same amount of free project time as most folks, I'd suggest to fix the major leaks and use the trailer until it is too much of a headache. Appliances may be on your short list and, depending on condition, may cancel the project before it starts.
Good luck with whatever route you take. I'm lovin' my rig, it is cozier and better built than anything I can buy.