A bonded manufacturer shall immediately file a new bond to supersede his current bond when (a) the corporate surety on the current bond becomes insolvent, (b) the appropriate TTB officer approves a request from the surety on the current bond to terminate his liability under the bond, (c) the payment of any liability under a bond is made by the surety thereon, (d) the amount of the bond is no longer sufficient under the provisions of § 41.121 and a strengthening bond has not been filed, or (e) the appropriate TTB officer considers a superseding bond necessary for the protection of the revenue.