79. Where a taxpayer has, before 1972 and after the commencement of the first fiscal period of a partnership ending after 1971, acquired an interest in the partnership from another person, sections 77 and 78 are applicable as if, for the purposes of paragraphs a and b of section 77 and paragraph a of section 78, the taxpayer had in respect of the interest, throughout the period commencing at the commencement of that fiscal period and ending at the time he acquired the interest, the same position in relation to the partnership as that which he would have had in relation thereto if, throughout that period, he had been the owner of the interest.