G. Sankaran, President

1. The facts of the case, briefly stated, are that the appellants were, during the material period, engaged in the manufacture of "Met rosyl DM Silicone Fluid" which was claimed by them as classifiable under sub-heading No. 3910.00 of the Schedule to the Central Excise Tariff Act, 1985, ("The Schedule", for short) attracting Central Excise duty at 35% ad valorem in terms of Serial Number 15 of the Table annexed to Central Excise Notfn. No. 132/86 dt. 1-3-1986. The notification provided inter alia the said concessional rate of duty for silicones in primary form if they were manufactured out of Chlorosilanes on which the excise duty, or the additional duty of customs, leviable thereon, as the case may be, had already been paid. The appellants were manufacturing the product using imported Chlorosilanes on which additional duty of customs had been paid. The Asstt. Collector, however, denied the benefit of the concessional rate of 35% ad valorem on the ground that the appellants had availed themselves of the Modvat credit of the additional duty of customs paid on Chlorosilane in terms of Central Excise Rule 57A and that, therefore, it (Chlorosilane) could no l