Exclusive jurisdiction is hereby conferred on the Secretary of the Interior to determine the heirs after notice and hearing under such rules and regulations as he may prescribe, and to probate the estate of any deceased restricted Indian, enrolled or unenrolled, of the Five Civilized Tribes of Oklahoma, whenever the restricted estate consists only of funds or securities under the control of the Department of the Interior of an aggregate value not exceeding $2,500: Provided, That where such decedent died prior to December 24, 1942, the distribution of such funds and securities, including the decedent’s share of any tribal funds, shall be made in accordance with the statute of descent and distribution applicable at the date of death: And provided further, That where the decedent dies subsequently to December 24, 1942 distribution of all such funds and securities, including tribal funds aforesaid, shall be effected in accordance with the statute of descent and distribution of the State of Oklahoma.