The relevant provisions of Rule 56A are as follows: "56A(1) . . 56A(2) The Collector may, on application made in this behalf and subject to the conditions mentioned in sub rule (3) and such other conditions as may, from time to time, be prescribed by the Central Government, permit a manu 270 facturer of any excisable goods specified under sub rule (1) to receive material or component parts of finished product (like Asbestos Cement), on which the duty of excise or the additional duty under section 3 of the (51 of 1975) (herein after referred to as the countervailing duty), has been paid in his factory for the manufac ture of these goods or the more convenient distribution of finished product and allow a credit of the duty already paid on such mate rial or component parts or finished product, as the case may be: Provided that no credit of duty shall be allowed in respect of any material or compo nent parts used in the manufacture of finished excisable goods (i) if such finished excisable goods produced by the manufacturer are exempt from the whole of the duty of excise leviable thereon or are chargeable to 'nil ' rate of duty, and (ii) . . Explanation.