Best advise would be to not have the same garage check over the vehicle that is selling it. You honestly think their mechanic is going to turn round and say "Yeah XYZ is fookered, it ain't worth £50 like that."
In fact, even better advice would be to buy a Defender :lol:
Seriously though, chances are it's nothing to worry about but you'd be best to get it checked independently. Or see if you can get a test drive in a few other Freelanders for comparison but it's not fool proof.