Regulation (EEC) No 1746/75 of the Commission of 7 July 1975 re-establishing the levying of customs duties on certain heavy oils for certain purposes, falling within subheadings 27.10 C I c), C II c) and C III c) and d), originating in developing countries, to which the preferential tariff arrangements set out in Council Regulation (EEC) No 3054/74 of 2 December 1974 apply