If the proof required by § 2352 of this title has not been filed within the time prescribed by that section, and if within such time it does not appear that letters testamentary or of administration have been issued in the domiciliary state, the Register of Wills shall forthwith upon the expiration of such time notify by mail the official or body of the domiciliary state charged with the administration of the death tax laws thereof with respect to such estate, and shall state in such notice so far as is known to the Register:
(1) The name, date of death and last domicile of such decedent,
(2) The name and address of each executor or administrator,
(3) A summary of the values of the real estate, tangible personalty and intangible personalty, wherever situated, belonging to such decedent at the time of the decedent's death and
(4) The fact that such executor or administrator has not filed theretofore the proof required by § 2352 of this title.
The Register shall attach to such notice a plain copy of the will and codicils of such decedent, if the decedent died testate, or, if the decedent died intestate, a list of heirs and next of kin so far as is known to such Register.