As a minimum, you want to see a history folder file that shows the van has had a service (with oil and filter change) every 12 months/12,000 miles (whichever comes sooner). Check the load area for damage and the tyres for uneven wear - both will imply the vehicle has been overloaded on a regular basis. For more used van buying advice, see: vans.honestjohn.co.uk/how-to-buy-and-sell/how-to-b.../