31 CFR 341.12: Lost, stolen, or destroyed bonds.

If a Retirement Plan Bond is lost, stolen, or destroyed, a substitute may be issued upon identification of the bond and proof of its loss, theft, or destruction. A description of the bond by denomination, serial number, issue date and registration should be furnished at the time the report of loss, theft, or destruction is made. Such reports should be sent to the Bureau of the Fiscal Service, Division of Transactions and Rulings, Parkersburg, WV 26101. Full instructions for obtaining substitute bonds will then be given.