In general
If the time has expired under section 6501 within which a tax may be assessed under chapter 12 (or under corresponding provisions of prior laws) on—
(A)#
the transfer of property by gift made during a preceding calendar period (as defined in section 2502(b)); or
(B)#
an increase in taxable gifts required under section 2701(d),
the value thereof shall, for purposes of computing the tax under this chapter, be the value as finally determined for purposes of chapter 12.