|(d) Enforcement of Reparation Orders.
(1) In case of violation of an order of the Commission for the payment of reparation, the person to whom the award was made may seek enforcement of the order in a United States district court having jurisdiction of the parties.
(2) In a United States district court the findings and order of the Commission shall be prima facie evidence of the facts therein stated, and the petitioner shall not be liable for costs, nor for the costs of any subsequent stage of the proceedings, unless they accrue upon his appeal. A petitioner in a United States district court who prevails shall be allowed reasonable attorney_s fees to be assessed and collected as part of the costs of the suit.
(3) All parties in whose favor the Commission has made an award of reparation by a single order may be joined as plaintiffs, and all other parties in the order may be joined as defendants, in a single suit in a district in which any one plaintiff could
maintain a suit against any one defendant. Service of process against a defendant not found in that district may be made in a district in which is located any office of, or point of call on a regular route operated by, that defendant. Judgment may be
entered in favor of any plaintiff against the defendant liable to that plaintiff.