(a)the [duty and interest, if any, paid on such duty][paid by the importer or the exporter, as the case may be, if he had not passed on the incidence of such [duty and interest, if any, paid on such duty] [Substituted by Act 40 of 1991, Section 10 (w.e.f. 20.9.1991). ] [to any other person; [Substituted by Act 40 of 1991, Section 10 (w.e.f. 20.9.1991). ]