(iii) it manufactures or produces articles, or operates one or more cold storage plant or plants, in any part of India, and has begun or begins to manufacture or produce articles or to operate such plant or plants, at any time within the period of 1[ thirty- three] years next following the 1st day of April, 1948 , or such further period as the Central Government may, by notification in the Official Gazette, specify with reference to any particular industrial undertaking;