No return may be made pursuant to section 4309 or 4329 of this title unless notice of claim has been filed: (a) in the case of any property or interest acquired by the United States prior to December 18, 1941, by August 9, 1948; or (b) in the case of any property or interest acquired by the United States on or after December 18, 1941, not later than one year from February 9, 1954, or two years from the vesting of the property or interest in respect of which the claim is made, whichever is later. No suit pursuant to section 4309 of this title may be instituted after April 30, 1949, or after the expiration of two years from the date of the seizure by or vesting in the Alien Property Custodian, as the case may be, of the property or interest in respect of which relief is sought, whichever is later, but in computing such two years there shall be excluded any period during which there was pending a suit or claim for return pursuant to section 4309 or 4329(a) of this title.