“that such deductions were not rightly allowed…. The Commissioners allowed a use of home deduction in the sum of£63 for the period1 December 1987 to20 February 1989 . That deductible item was, as were all other deductible items, said to be deductible under the provisions of section 74. I do not see how a use of home deduction can be related to section 74. Furthermore, the evidence does not show that a use of home deduction can be justified on any other ground”