Effect of statutory amendment: prior rights, obligations and prosecutions preserved despite repeal or amendment of instruments. Amendments, repeals, supersessions or rescissions of rules, notifications or orders under the Act do not revive matters not in force at the change's effective time, nor do they affect previous operation, acquired rights, accrued obligations, or penalties and punishments; investigations, proceedings and remedies connected with those matters may be instituted, continued or enforced as if the instrument had not been amended, repealed, superseded or rescinded.