Limitations on actions brought

(1) No action based upon any public security authorized and issued on or after July 1, 1969, shall be commenced more than eighteen years after the final maturity date of the issue of which such public security is one. (2) No action based upon any public security issued prior to July 1, 1969, shall be commenced more than eighteen years after the final maturity date of the issue of which such public security is one. (3) No action based upon any claim for interest accrued on any public security, whether said claim is evidenced by interest coupons or not, shall be commenced after action based upon said public security has been barred. (4) The provisions of this section shall be inoperative as to any public security unless the treasurer of the issuing political subdivision at least six months and not more than twelve months prior has sent to the holder of record of such public security, at his last-known address as shown on the books of such treasurer, a notice of the provisions of this section. A copy of such letter of notice held in such treasurer's records shall be conclusive proof that the requirements of this subsection (4) have been complied with.