If MARAD fails to give written notice of allowance or disallowance of a claim in accordance with § 327.6 within sixty calendar days following the date of the receipt of such claim by the proper person designated in § 327.5, such claim will be presumed to have been “administratively disallowed,” within the meaning in section 1(a) of 50 U.S.C.A. 4701 (a).