7Any application by the Commission under section forty-six of this Act which is pending on the vesting date, and any application required to be made by 'the Commission under section forty-eight of this Act which has not been made on the vesting date, shall be proceeded with, or made, by the London Board and the Railways Board jointly:
Provided that if the application under section forty-six or the notice under section forty-eight of this Act was concerned with charges for the services of one of the Boards exclusively, the application shall be proceeded with or made by that Board alone.