Section 9--704. Security Interest Unperfected Before Effective Date. A security interest that is enforceable immediately before Revised Article 9 takes effect but which would be subordinate to the rights of a person that becomes a lien creditor at that time: (a) remains an enforceable security interest for one year after Revised Article 9 takes effect; (b) remains enforceable thereafter if the security interest becomes enforceable under Section 9--203 when Revised Article 9 takes effect or within one year thereafter; and (c) becomes perfected: (1) without further action, when Revised Article 9 takes effect if the applicable requirements for perfection under Revised Article 9 are satisfied before or at that time; or (2) when the applicable requirements for perfection are satisfied if the requirements are satisfied after that time.