( 1 ). The Union of India, the Collector of Customs, Bombay and the Assistant Collector of Customs. Special Valuation Branch, Bombay are the appellants in this appeal. M/s Mahindra and Mahindra Limited, Bombay are the respondents. The matter herein arises under the Customs Act, 1962. The respondents filed Writ Petition No. 3167 of 1986 in the High court of Bombay and assailed the order dated 20/9/1985, passed by the Assistant Collector of Customs, evidenced by Ext. K and the appellate order dated 2/9/1986 passed by the Collector of Customs (Appeals) affirming the said order, evidenced by Ext. M. A learned Single Judge by judgment dated 27/7/1988 quashed the aforesaid orders and also ordered refund of excise duty recovered from the respondents during the period from June 1984 onwards, after verifying the particulars submitted by the respondents. The appellants herein filed Appeal No. 237 of 1987 before a division bench of the Bombay High court. The division bench, by judgment dated 7/3/1991, 8/3/1991, affirmed the decision of the learned Single Judge. The prayer for the issue of a certificate to appeal to this court was also declined. Thereafter, the appellants moved this court in S