(1) When an order of reference has been made, the parties may each nominate the number of arbitrators specified in the order, and the Revenue-officer shall nominate one other arbitrator.
    (2) The Revenue-officer may, for reasons to be recorded by him, make an order disallowing any nomination made by either party and requiring the party to make another nomination within a time to be specified in the order.
    (3) An order under the last foregoing sub-section shall be final.