All acts performed prior to the codification of the ordinance in this section requiring the use of the city seal, and all papers sealed with the city seal since its first adoption, are declared to be due and legal acts on papers of the city, and all acts performed prior to the codification of the ordinance in this section and all proceedings and all papers impressed with the city seal since that date are validated and declared legal. (Ord. 452 § 1 (part), 1990)