(

a) If—

(1) The property is acquired by gift on or after the date of the enactment of this section, the basis shall be the basis determined under

Section 24914, increased (but not above the fair market value of the property at the time of the gift) by the amount of federal gift tax paid with respect to such gift, or

(2) The property was acquired by gift before the date of the enactment of this

section and has not been sold, exchanged, or otherwise disposed of before such date, the basis of the property shall be increased on such date by the amount of federal gift tax paid with respect to such gift, but such increase shall not exceed an amount equal to the amount by which the fair market value of the property at the time of the gift exceeded the basis of the property in the hands of the donor at the time of the gift. (

b) For purposes of subsection (a), the amount of federal gift tax paid with respect to any gift is an amount which bears the same ratio to the amount of gift tax paid under

Chapter of Subtitle B of the Internal Revenue Code of with respect to all gifts made by the donor for the calendar year in which such gift is made as the amount of such gift bears to the taxable gifts (as defined in

Section 2503(

a) of the Internal Revenue Code of but computed without the deduction allowed by

Section of the Internal Revenue Code of 1954) made by the donor during such calendar year. For purposes of the preceding sentence, the amount of any gift shall be the amount included with respect to such gift in determining (for the purposes of

Section 2503(

a) of the Internal Revenue Code of 1954) the total amount of gifts made during the calendar year, reduced by the amount of any deduction allowed with respect to such gift under

Section of the Internal Revenue Code of 1954 (relating to charitable deduction) or under

Section of the Internal Revenue Code of 1954 (relating to marital deduction). (

c) For purposes of subsection (a), where the donor and his spouse elected, under

Section of the Internal Revenue Code of to have the gift considered as made one-half by each, the amount of gift tax paid with respect to such gift under

Chapter of Subtitle B of the Internal Revenue Code of shall be the sum of the amounts of tax paid with respect to each half of such gift (computed in the manner provided in subsection (b)). (

d) For purposes of

Section 24917, an increase in basis under subsection (

a) shall be treated as an adjustment under

Section 24916. (

e) With respect to any property acquired by gift before 1955, references in this

section to any provision of this part shall be deemed to refer to the corresponding provision of the Federal Internal Revenue Code of or prior revenue laws which was effective for the year in which such gift was made.