amount, with respect to each month of such period within the taxable year, equal to the adjusted basis of the facility at the end of such month divided by the number of months (including the month for which the deduction is computed) remaining in the period. Such adjusted basis at the end of the month shall be computed without regard to the amortization deduction for such month. The amortization deduction above provided with respect to any month shall, except to the extent provided in subsection (g) of this section, be in lieu of the deduction with respect to such facility for such month provided by section 23(l), relating to exhaustion, wear and tear, and obsolescence. The sixty-month period shall begin as to any emergency facility, at the election of the taxpayer, with the month following the month in which the facility was completed or acquired, or with the succeeding taxable year.
'(d) Termination of amortization period.
'(1) If the President has proclaimed the ending of the emergency period (as defined in subsection (e)), or if the Secretary of War or the Secretary of the Navy has, in accordance with regulations prescribed by the President, certified to the Commissioner that an emergency facility ceased, on the date specified in the certificate, to be necessary in the interest of national defense during the emergency period, and if the date of such proclamation or the within sixty months from the beginning of the date specified in such certificate occurs amortization period with respect to such emergency facility, then the taxpayer may elect (in accordance with paragraph (4) of this subsection) to terminate the amortization period with respect to such emergency facility as of the end of the month in which such proclamation was issued or in which occurred the date specified in such certificate, whichever is the earlier. In such case the amortization period with respect to such facility shall end with the end of the month in lieu of the end of the sixty-month period.
'(4) The election provided in paragraph (1), (2) or (3) shall be made by filing with the Commissioner, in such manner, in such form, and within such time, as the Commissioner with the approval of the Secretary may by regulations prescribe, a statement of such election. When such election has been so made, then, under regulations prescribed by the Commissioner with the approval of the Secretary, the taxes for all taxable years, beginning with the taxable year in which the amortization period began, shall be computed in accordance with an amortization deduction computed in accordance with the method provided in subsection (a), but using (in lieu of the sixty-month period provided in such subsection) the amortization period specified in paragraph (1), (2), or (3), as the case may be.
'(2) Emergency period. As used in this section, the term 'emergency period' means the period beginning January 1, 1940, and ending on the date on which the President proclaims that the utilization of a substantial portion of the emergency facilities with respect to which certifications under subsection (f) have been made is no longer required in the interest of national defense.
'(h) Payment by United States of unamortized cost of facility. If an amount is properly includible in the gross income of the taxpayer on account of a payment with respect to an emergency facility and such payment is certified as provided in this paragraph, then, at the election of the taxpayer in its return for the taxable year in which such amount is so includible-
'(1) The amortization deduction for the month in which such amount is so includible shall (in lieu of the amount of the deduction for such month computed under subsection (a)) be the amount so includible, but such deduction shall not be in excess of the adjusted basis of the emergency facility as of the end of such month (computed without regard to any amortization deduction for such month). Payments referred to in this paragraph shall be payments the amounts of which are certified under such regulations as the President may prescribe, by either the Secretary of War or the Secretary of the Navy as compensation to the taxpayer for the unamortized cost of the emergency facility made because-
'(A) A contract with the United States involving the use of the facility has been terminated by its terms or by cancellation, or
'(B) the taxpayer had reasonable grounds (either from provisions of a contract with the United States involving the use of the facility, or from written or oral representations made under authority of the United States) for anticipating future contracts involving the use of the facility, which future contracts have not been made. * * * '