The provisions of Article 201 (Tax Withheld from Retirement Income) of the new Act, and Appended Table VIII of the new Act and the attached table to that Table, apply to severance pay or other such compensation prescribed in Article 199 (Obligation to Withhold Taxes from Retirement Income) of the new Act (hereinafter referred to as "severance pay or other such compensation") which is payable during 1975 and is paid on or after the effective date, and the provisions then in force continue to govern severance pay or other such compensation payable during that year which was paid before the effective date.