Where a contributor resigns from service or where a contributor has died, then the amount standing to the credit of the contributor in the member's annuity reserve account shall be paid to him or his estate or to the person named in any beneficiary certificate filed by the contributor with the board. When a contributor or a beneficiary has died and there shall be due to the estate of such contributor or beneficiary a sum less than one hundred dollars ($100), and letters testamentary or of administration have not been taken out on the estate of such contributor or beneficiary within six months of death, the board may pay the amount due on the claim of the undertaker or to any person or persons or political subdivision who or which shall have paid the claim of the undertaker.