If MarAd fails to give written notice of allowance or disallowance of a claim in accordance with §327.6 within sixty (60) calendar days following the date of the receipt of such claim by the proper person designated in §327.5, such claim shall be presumed to have been “administratively disallowed,” within the meaning in section 1(a) of 50 U.S.C. App. 1291(a).