Nice looking BJ74. Pretty standard rust areas on that. Of course you know there will be more once you start digging in. That rear door does look dented from the photo.
I would always try and get a compression test if possible. I can tell you the first thing I would do if completely refresh that cooling system. It's leaking already and I bet that radiator needs some help. The 13BT are great diesel engines. The PO of mine had a hose blow on the freeway which blew the headgasket at 305,000miles. I did a full rebuild and she runs fantastic. I'd replace waterpump all hoses and recondition/test that radiator and flush the whole system and heater core, new thermostat.
If you can drive before, I'd get it nice and warmed up to check the coolant/overflow for signs of a blown HG. Not a common problem, but with the looks of some leaking coolant hoses, I would definitely check that.
I would also plan on injector rebuild, cheap and will help out. Unless the pump is leaking all over or not running great, it should be good to go.
Most of the other stuff is pretty standard leaf sprung land cruiser issues, axles, suspension, steering joints, tie rod ends etc.
the underneath looks "coated" or painted. Could be hiding a lot of rust, or maybe it has been preventative and touched up. I would just double check that.
Other typical things like leaks and who knows what other weird things the Previous Owners did.