I had a 1970 VW camper bus for years and years. As long as you changed the oil, it was stone-cold reliable. Slow as poo in the mountains, but still great fun. A little stinky when it leaked oil on the heat exchanger. Had no heat untill you had driven for 30 minutes or so....(carry a blanket!).

Tell the boy to make sure all the fuel lines and clamps are in good shape. And if it does catch fire, put it out with a fire extiquisher, not water (may want to carry one).