Deemed credit on steel scrap preserved for transitional balances; subsequent credit requires production of duty payment documents. Deemed credit on steel scrap was available without duty payment documents prior to 29-8-1986 but that facility was withdrawn with effect from 29-8-1986, making credit on scrap admissible thereafter only on production of duty payment documents. Deemed credit balances allowed under the earlier order dated 7-4-1986 and standing on 28-8-1986 may be used for payment of duty on final products.