The Eurovan camper was basically an extended wheelbase Eurovan imported specifically for Winnebago. While common in Europe, these vans didn't get imported here.
Tell your alignment guy to try the specs for a MV model. A VW or Winnebago dealer that sold the Eurovan camper, there were only a select few, should have the specs and equipment for a proper alignment.
There should be some adjustment possible with the rear wheels. A couple of degrees caster and camber only. If it cannot be brought into spec, then you have something bent. You basically loosen the control arm bolts and there should be some adjustment.