In the case of property acquired before , if the basis otherwise determined under this subtitle, adjusted (for the period before ) as provided in section 1016, is less than the fair market value of the property as of , then the basis for determining gain shall be such fair market value. In determining the fair market value of stock in a corporation as of , due regard shall be given to the fair market value of the assets of the corporation as of that date.March 1, 19131913-03-01March 1, 19131913-03-01March 1, 19131913-03-01March 1, 19131913-03-01