How does "sub-paragraphs (3)" and "(4)" change after the Constitution (Seventh Amendment) Act, 1956?
Sub-paragraphs (3) and (4) changed after the Constitution (Seventh Amendment) Act, 1956 as follows:

(3) Any person who, immediately before the commencement of the Constitution (Seventh Amendment) Act, 1956, was holding office as the Chief Justice of the High Court of a State specified in Part B of the First Schedule and has on such commencement become the Chief Justice of the High Court of a State specified in the said Schedule as amended by the said Act, shall, if he was immediately before such commencement drawing any amount as allowance in addition to his salary, be entitled to receive in respect of time spent on actual service as such Chief Justice, the same amount as allowance in addition to the salary specified in sub-paragraph (1) of this paragraph.

(4) Any person who, immediately before the commencement of the Constitution (Seventh Amendment) Act, 1956, was holding office as a Judge (other than the Chief Justice) of the High Court of a State specified in Part B of the First Schedule and has on such commencement become a Judge (other than the Chief Justice) of the High Court of a State specified in the said Schedule as amended by the said Act, shall, if he was immediately before such commencement drawing any amount as allowance in addition to his salary, be entitled to receive in respect of time spent on actual service as such Judge, the same amount as allowance in addition to the salary specified in sub-paragraph (1) of this paragraph.