24Where compensation became or becomes payable as mentioned in paragraph 23 of this Schedule, and at any time an amount became or becomes recoverable in respect thereof under section 29 of the Act of 1954, as applied by section 46 of that Act, or under section 159 of this Act as applied by Schedule 24 to this Act to compensation under Part V of the Act of 1954, then, for the purposes of Part VII of this Act, paragraph 23. of this Schedule shall have effect as from that time as if the principal amount of that compensation had been reduced by a sum equal to seven-eighths of the amount which so became or becomes recoverable.