The drawback on beer provided for in paragraph 7 (3) of the Imposition of Duties (No. 221) (Excise Duties) Order, 1975, shall in respect of beer exported as merchandise, or shipped for use as stores, during the period from the 25th day of February, 1980, to the 31st day of December, 1980, be calculated at the rate of the excise duty paid on the beer less an amount of £0.26 on every 36 gallons of beer of which the original specific gravity was 1,055 degrees.