A claim for disability under section
1643b
(b) of this title may be considered if it is filed by the disabled person or by his successors in interest; and a claim for death under section
1643b
(b) of this title may be considered if filed by the personal representative of decedent’s estate or by a person or persons for pecuniary losses and damage sustained on account of such death. A claim shall not be considered under this section unless the disabled or deceased person was a national of the United States at the time of injury or death and if considered, shall be considered only to the extent the claim has been held by a national or nationals of the United States continuously until the date of filing with the Commission.