It's much easier to deal with a camper that has a clean title. I really don't like to deal with any other situation. Each state has its own set of rules when it comes to this so I have little advice except to do your research. I don't recommend staring any work on a camper unless you've secured the title in your name.

This is a question of preference and opinion. There is some debate on how old a camper has to be in order to be considered "Vintage". Some enthusiast says 1973 is the cut-off while others will accept camper up until the late 1970s. If you plan on belonging to a specific vintage trailer club, then you might want to research their specific guidelines. Other than that, you should use your own judgment....If you like it, then age doesn't' matter.

Again...do you like it? Many vintage camper models have a large following. There are websites and social media sites devoted to them. The more popular the make and model is, the more you can sell your restored camper for. But...sometimes that means you'll pay more for the unrestored camper as well. The important thing is to buy what you like, have a vision for the completed project and have fun with it.

Consider the scope of your potential project. I don't recommend starting off with a 24-foot aluminum camper that needs a complete frame-up restoration. You could get discouraged and overwhelmed before you even start. Start with a small, 14-16 foot trailer. Maybe consider one that doesn't have a bathroom so you don't have to deal with a black-water tank for your first project. Just a thought....

Look for bowing sides or sagging roof lines. This is a good indication that a piece of the framing has been compromised. Don't get me wrong, it can be fixed, just know that you'll be taking the aluminum siding off to access the damage. By the way, if the siding is off you might as well access the electrical and insulation. 🙂

Speaking of electrical..... Maybe you are very comfortable with this but I wasn't. I learned A LOT! If running or fixing electrical systems is your thing then you're my hero! Remember that most campers have 12v and 110 power along with a trailer tail light system. You'll need the tail/brake lights to work when towing your project home. (Or you can put your camper on an auto trailer.)
Propane lines should be tested with leak detector fluid before using them long term.
Water systems are fairly simple but I can tell you that I went to the hardware store more times when installing mine than any other thing. Typically a new faucet and/or pump may be required.

Water pump and fuses. I'm going to need to upgrade that.

Most of them are NOT! If the wood paneling has watermarks, discoloration or delamination then it's been wet. This happens most frequently around the roof vent, windows and corners. The good news is the wood can be repaired. But first, you need to stop the leak.

Check for broken leaf springs. (Yep, you'll have to put your head under there and shine a flashlight on them.) Leaf-springs can be replaced but it's not something I'd like to tackle.
The same goes for brakes. Lots of people do them but I'd probably take it to a repair shop.
Most of the time tires will need to be replaced. Trailer tires are only good for 10 years regardless of their wear.
Wheel bearings are easy to replace or repack. There are lots of YouTube videos on how to do this. Pretty simple.
After you access the lights, tires, and brakes you'll have to decide if you can safely tow the camper to your project site. Maybe putting it on an auto trailer a better option.

Check for dents, damage, and missing siding. You can still purchase siding for vintage campers and some repairs are possible. Bondo and a lot of sanding can make siding look better but holes WILL lead to water damage if you don't repair them.

There are lots of sites that sell vintage trailer parts and appliances so it's possible to find replacements, but a complete camper will save you $$.