Notwithstanding the provisions of the Income Tax Act, the Corporation Tax Act and the Local Tax Act as amended by the provisions of Article 20 through the preceding Article of the Supplementary Provisions, the provisions then in force continue to govern the federations of vocational training corporations and the central association of vocational training corporations prescribed in Article 5, paragraph (1) of the Supplementary Provisions, the Central Trade Skill Testing Association and the prefectural trade skill testing associations.