Notwithstanding any other provision of law, a person holding a credential issued under the laws and regulations in effect on or before December 31, 1971, authorizing teaching in grades 7 to 12, inclusive, or grades 7 to 9, inclusive, in the secondary schools may be assigned, with his or her consent, to teach any subject authorized on his or her credential in grades 5 and 6 or grade 5 or grade 6 in a departmentalized program in a school composed of grades 5, 6, 7, and 8 or grades 6, 7, and 8.

Notwithstanding any other provision of law, a person holding a credential issued under the laws and regulations in effect on or before December 31, 1971, authorizing administration in grades 7 to 12, inclusive, in the secondary schools may be assigned, with his or her consent, to provide administration for grades 5 and 6 or grade 6, in a school composed of grades 5, 6, 7, and 8 or grades 6, 7, and 8.