Bestbox 501-A DAF 600 variations known to me:

 

    1: Grey wheels with black tyres, unpainted articulated base

 

    2: Grey solid wheels, unpainted articulated base

 

    3: Grey solid wheels, black articulated base

 

    4: Grey solid wheels, blue articulated base

 

    5: Grey solid wheels, grey smooth base

 

   6: Grey solid wheels, blue smooth base

 

   Box variations