(1) Where, after the commencement of this Act, a person dies wholly or partly testate leaving a spouse or civil partner or children or both spouse or civil partner and children, the provisions of this Part shall have effect.
(2) In this Part, references to the estate of the testator are to all estate to which he was beneficially entitled for an estate or interest not ceasing on his death and remaining after payment of all expenses, debts, and liabilities (other than estate duty) properly payable thereout.