There would be a bit of surface rust going on all right, you'd expect that with all ex beach patrol vehicles.
They must be very busy down there patrolling !
But, at 5,000 to 30,000 odd km should be ok body wise, undercarriage could be flushed, pressure cleaned, rust proofed, blackened as needed.
They would be good buys at those low km, all extra cabs, and they have suicide doors yeah ? Perfect for cab fridge and storage 2 seat touring setup.
If they are anything like the rangers and dmax’s cruising around the airport second runway project after a couple of years $610 is way too much to pay. They are bin jobs after being in that environment. Their panels are ok with the electro zinc they do these days but the chassis and anything bolted to them are well past the ‘surface rust’ stage.