On receipt of a statement under the last foregoing paragraph, the Assessor shall (if necessary) adjust the Gas Board’s basic rateable valuation, calculate the rateable value of the lands and heritages which that Board are to be treated as occupying during the year in question in each separately rated area, and shall F1enter such rateable values in the valuation roll to be made up by him and notify the amount thereof to the F2local authority concerned and to the Board before the eighth day of September in that year.F1direct the local assessor under section 5 of the M1Local Government (Scotland) Act 1975 to enter the lands and heritages at such rateable values in the valuation roll and shall notify the amount of the rateable values to the rating authority concerned and to the Board before such date as may be prescribed.