Effective July 1, 1972, officers and employees who were engaged prior to said date in the performance of powers, duties, and functions of any existing state agency which becomes a part of the department of revenue created by this act or the powers, duties and functions of which are transferred to the department of revenue created by this act, and who, in the opinion of the secretary of revenue are necessary to perform the powers, duties, and functions of the department of revenue, or of any division, section, or other unit thereof, shall become officers and employees of the department of revenue, and shall retain all retirement benefits and all rights of civil service which such officer or employee had before July 1, 1972, and their services shall be deemed to have been continuous. All transfers and any abolishment of positions of personnel in the classified civil service shall be in accordance with civil service laws and rules and regulations. Notwithstanding the foregoing provisions of this section, no person, who occupies a position on the effective date of this act which position (or a parallel position thereto) is provided by this act to be in the unclassified service, shall retain any rights of classified civil service. This section shall not apply to persons who are members of the motor vehicle reciprocity commission or port of entry board.