Where there is no record of the purchase price or production cost of any asset of a company or of any price, expenses or costs relevant for determining its purchase price or production cost in accordance with paragraph 26, or any such record cannot be obtained without unreasonable expense or delay, its purchase price or production cost shall be taken for the purposes of paragraphs 17 to 23 to be the value ascribed to it in the earliest available record of its value made on or after its acquisition or production by the company.