(a) [General rule: perfection by filing.]
(b) [Exceptions: filing not necessary.]
The filing of a financing statement is not necessary to perfect a security interest:
(2) that is perfected under Section 9-309 when it attaches;
(3) in property subject to a statute, regulation, or treaty described in Section 9-311(a);
(7) in a certificated security which is perfected by delivery of the security certificate to the secured party under Section 9-313;
(10) that is perfected under Section 9-316.
(c) [Assignment of perfected security interest.]
If a secured party assigns a perfected security interest or agricultural lien, a filing under this article is not required to continue the perfected status of the security interest against creditors of and transferees from the original debtor.