I had a hard look at as Costa Rican BJ40 last year....To the point where I had booked a flight to go get it. I pulled chocks at the last minute because it just didn't feel right. Call it superstition, but your gut is usually right when it comes to big decisions.
The biggest concern with these trucks is how they were maintained. South America isn't notorious for the best service and most of these were work trucks that saw hard lives. At that price point, you can be getting into a much better spec'd rig (heater, 3b or petrol 2f) and some more piece of mind.
I waited and scored a BJ41 that was mostly original and was a much better foundation for where I wanted start..all for less money than I was consider the South American BJ40 for.
So, my lessons learned during my long search were these.
1. Don't jump.
2. Have someone go look it over and drive it and take a ton of pictures if you can't do it yourself.
3. Know what you want it for.
4. Be aware of how slow the B and 2B engines are.
5. Look for dodgy repairs on the frame (suspension mounts, rear cross member, etc.)
6. Take a good look at the rear of the tub on the inside. The seams will tell you all you need to know about what was cut and repaired.
7. If you REALLY want a Cruiser, then you SHOULD be enjoying the entire process. If any of it becomes a headache for you, then ownership may be worth reconsidering. Bolts are going to break, things will go wrong, and you have to be OK with that.
8. Take a magnet and go over the whole body and frame to ID bondo sections and metal sections.
9. There is a lot of truth to the advice on here that states "I'd rather be able to see the bad spots than have it look pretty and not know what lurks beneath".
10. Make sure the paper trail is there. It can get sticky fast with imported rigs. For example, in CT they do not issue a title. SO, I only have the PO's title signed over to me. That's enough, but an important piece to have. It's worth it to have the current owner do the leg work to get something tangible in hand. Once the deal is done, you could be stuck.
11. Let the rig run up to temp and make sure it doesn't overheat or do things it shouldn't.
12. Read up on the FAQ section on what to look for when buying. It's a bible.
Good luck!