For the purpose of applying Article 140, paragraph (1) (Claim to Be Issued a Refund Based on Carryback of Net Loss) or Article 141, paragraph (1) (Claim by an Heir or Other Person to Be Issued a Refund Based on Carryback of Net Loss) of the new Act (including as applied mutatis mutandis pursuant to Article 166 (Application Mutatis Mutandis to Nonresidents) of the new Act; the same applies hereinafter in this Article) where there is a Net Loss in 1966, the amount of income tax that serves as the basis for calculating the refund under those provisions is to be the amount of income tax calculated by applying Part II, Chapter III, Section 1 (Tax Rates) of the former Act.