The benefit or burden of any assets or liabilities of an existing State not dealt with in the foregoing provisions of this Part shall—
         (a) if there be only one successor State, pass to that State, and
         (b) if there be two or more successor States, pass to the principal successor State in the first instance, subject to such financial adjustment as may be agreed upon between all the successor States, before the 1st day of October, 1957, or in default of such agreement, as the Central Government may be order direct.