Mo. Rev. Stat. § 400.9-704: Security interest unperfected before effective date.

A security interest that is enforceable immediately before July 1, 2001, but which would be subordinate to the rights of a person that becomes a lien creditor at that time:

(1) Remains an enforceable security interest for one year after July 1, 2001;

(2) Remains enforceable thereafter if the security interest becomes enforceable under section 400.9-203 on July 1, 2001, or within one year thereafter; and

(3) Becomes perfected:

(A) Without further action, on July 1, 2001, if the applicable requirements for perfection under this act are satisfied before or at that time; or

(B) When the applicable requirements for perfection are satisfied if the requirements are satisfied after that time.