(b)where the building, machinery, plant or furniture is sold, the price for which it is sold, so, however, that where the actual cost of a motor car is, in accordance with the proviso to clause (1) of section 43, taken to be twenty-five thousand rupees, the moneys payable in respect of such motor car shall be taken to be a sum which bears to the amount for which the motor car is sold or, as the case may be, the amount of any insurance, salvage or compensation moneys payable in respect thereof (including the amount of scrap value, if any) the same proportion as the amount of twenty-five thousand rupees bears to the actual cost of the motor car to the assessee as it would have been computed before applying the said proviso;
