I bought a 1975 Corsair trailer on Ebay recently. I got it for just $355 and it is going to need quite a bit of work, but it looks pretty straight overall.
Actually, it was my wife that really wanted it!
Anyway... My aging 1989 Ford F150, manual transmission, 302 V8, and 4 wheel-drive, was set up with just a class III hitch set-up. You know, that kind that attaches to the step-bumper of the truck... Well, it is rated at 4000 pounds, and the trailer was purported to be a tad under that at 3850 pounds. However, standing next to the trailer, it "felt" heavier than that. After much searching, I found the plate which puts the GVWR at 5500 pounds. That is a whole lot different to what it was advertised as!
I went out and bought (from a wrecker) a very fine condition hitch-receiver, rated at 10,000 pounds, and found a Tekonsha Voyager brake controller in a very late model truck. So, I have all the wiring, the controller, and a hitch-receiver that will be able to easily deal with the weight of the trailer. I have all the plugs etc now. Everything - and I do mean EVERYTHING!!! - cost a shade over a hundred bucks.
So.... What do I have to watch out for? Does anyone know much about my type of truck and what connects to where in it?? Should I go ahead and replace all the wire to the brakes in the trailer? And WHERE is the breakaway system likely to be located? I looked for it the other day when I was out where the TT is currently stored, but could not locate it... If there isn't one, will the trailer be towable? Or will I need to spend a bunch of time setting up a breakaway system before I can attempt to move it?
If it has a breakaway system, there will be a separate battery on the trailer, and a small square box with a pin in it on the trailer hitch, and a cable you hook to the truck hitch. They are relatively easy to install if you don't have one.