Would your solution work for the following scenario? While design considerations for such a domain model is debatable, it is a valid way to represent PK fields which are inevitability inheritable from a parent PK by adding one additional column for a child entity's unique PK.

public class WorkOrder {
  public static class WorkOrderId {
  }
}
public class WorkOrderComponent {
  public static class WorkOrderComponentId extends WorkOrderId {
  }
}