Any member of the police department who shall have been retired and shall be receiving a pension on the eighth day of January, 1932, and any widow, child, children or parents of a deceased member of the department who shall be receiving a pension on the 8th day of January, 1932, shall continue to receive such pension, subject to the provisions of Section 8.540 governing the payment of pensions. Such pension shall be paid by the Retirement System, but no other benefits shall be provided for such retired members, widows, children or parents, except that upon the death of any such member who is receiving a pension under this section and regardless of the cause of death, a death benefit shall be paid to his estate or designated beneficiary, the amount of which shall be determined in the manner prescribed by the Board of Supervisors.