Any former justice of the Supreme Court or judge of any of the several circuit courts of this state who became a supernumerary justice or judge under the applicable laws of this state prior to September 18, 1973, may elect to come under the provisions of Article 1 of this chapter by filing with the Clerk of the Supreme Court of Alabama, within one year after October 1, 1976, an instrument in writing electing to come under the provisions of Article 1 of this chapter.