You can easily find a Kettenkrad and a Kubel at that scale. That's a start. Scale Model Accessories have a number of mixed media kits in 1/76 (close enough!) that can fit onto airfield dioramas: trucks (MAN, Opel, German Ford,...and staff cars (Mercedes, Skoda, Praga, Daimler-Puch, Steyr, Simca, Fiat,.. ) and recently, special sets of figures pushing aircraft around. They also have radio trucks, Ambulance trucks, generators,...