1. If the windshield is original then chances are there is some rust in the corners of the windshield gasket. Peal part of the rubber back and take a peak.
2. The drip rails in the roof is a common rust spot on the FJ60's. If you have rust check the support beams. If they are rusty too then chances are its bad!
3. Ah yes the ol' tailgate. This is the first place you'll notice rust starting to build up. Open the tailgate and look at the hinges on the inside. Even a novice and tell if someone tried to patch it.
4. This is probably the most important part because it's the frame. You might have to drop the spare tire in order to see it, but check the back frame rails for rust build up.
5. Put the back seat down and gently peel back the inner wheel well cover. Most trucks have rust here. It's not a deal breaker, but should be noted.
6. This spot is very easily noticed. If the rust is really bad I would suggest replacing the whole fender, otherwise it will be hard to connect the lower chrome molding.
7. This is the obvious spot that every FJ60 and FJ62 will start to rust out. Run your finger on the inner rear wheel well and you can tell if it's a patch job, or original. If you still can't tell then look at how the rear mud flap is attached. If it doesn't have a mud flap then it has probably been patched.