Sections 76-901 to 76-907 shall become operative on January 1, 1966, or immediately upon the repeal of the federal stamp act on deeds of conveyance of real estate whichever is later. If the repeal of the stamp tax levied by the federal government is conditional upon the levy of a comparable tax by the state, then sections 76-901 to 76-907 shall become operative on the first day of the third month following the adoption of such a law by the federal government. The month in which the federal act is adopted shall be counted as the first month in determining the operative date of sections 76-901 to 76-907.