(7)
In the event of the death, disability, or separation from service of the custodian of any documentary material produced under any demand issued under this section or the official relief of such custodian from responsibility for the custody and control of such material, the Attorney General shall promptly—
(i)
designate another racketeering investigator to serve as custodian thereof, and
(ii)
transmit notice in writing to the person who produced such material as to the identity and address of the successor so designated.
Any successor so designated shall have with regard to such materials all duties and responsibilities imposed by this section upon his predecessor in office with regard thereto, except that he shall not be held responsible for any default or dereliction which occurred before his designation as custodian.