5. The following amendments shall be made in the Estate Duty Act, 1950 (X of 1950), namely:- (1) Throughout the Act, for the words “Central Board of Revenue” the words “National Board of Revenue” shall be substituted and shall be deemed to have been so substituted on the sixteenth day of December, 1971; (2) in section 2, in clause (3), for the words, figure and commas “Central Board of Revenue constituted under the Central Board of Revenue Act, 1924,” the words, figure and commas “National Board of Revenue constituted under the National Board of Revenue Order, 1972,” shall be substituted; and (3) in section 59A, in sub-section (1), the words “in the prescribed form” shall be omitted and shall be deemed to have been so omitted on the 1st day of July, 1971.