Section 51B. (1) Said classification and compensation plans shall be amended so that each office and position shall be allocated by said board to the proper job group in the following salary schedule; except that, in the case of elected officials, patient help, part time officers or employees, or in unusual circumstances, the board may fix salaries or wages for individual positions upon notice to the county commissioners and employing authority, and in such cases the positions shall not be allocated in said salary schedule:

(1A) Notwithstanding the provisions of paragraph (1), in any county, which by vote of the county commissioners, accepts the provisions of this paragraph said classification and compensation plans shall be amended so that each office and position shall be allocated by the board to the proper job group in the following salary schedules; except that, in the case of elected officials, court stenographers, patient help, part-time officers or employees, or in unusual circumstances, the board may fix salaries or wages for individual positions upon notice to the county commissioners and employing authority, and in such cases the positions shall not be allocated in said salary schedules:

(2) Except as otherwise provided by law, after a person has been allocated to the above salary schedule, he must render a minimum of one year of service in the step-in-range of the job group to which his office or position has been allocated before he can be moved into the next higher step-in-range of the same job group; provided, however, when computing the date when salary increments shall become due after the initial allocation to a step-in-range, subsequent steps shall be due annually on the anniversary of the effective date of assignment to a rate within a salary grade in the salary schedule in effect immediately prior to July first, nineteen hundred and fifty-seven; and, provided further, in the event a person has already served a period in excess of twelve months in said step-in-range in the salary schedule in effect prior to said date, the increment step to the next step-in-range shall be due immediately upon assignment to a step-in-range on said date, and any subsequent steps shall be due annually on the effective date of the salary schedule.

(3) Daily rates of per diem employees shall be computed on the basis of their assigned job groups.

(4) Said board may permit the recruitment of employees in a job group at a rate above the minimum; provided, that said board has first determined, on request of the appointing authority and the county commissioners, that an emergency exists because of lack of sufficient employees, lack of housing facilities, isolation from regular transportation facilities, or other unusual conditions. Any such permit shall remain in effect until rescinded by said board, but shall not be in effect longer than one year unless renewed in like manner and with like approval. Whenever said board permits the recruitment of employees in a job group at a rate above the minimum rate in said job group, all employees in the same classification in the same county who are below such rate of recruitment shall be advanced to said higher rate in the salary schedule; provided, that the board may, by special vote declare that such increase for other employees shall take effect only in a particular institution or specific area.

(4A) Said board may permit the recruitment of agents or instructors appointed for purposes specified in section forty-three of chapter one hundred and twenty-eight at a rate above the minimum and within the grade to which the requested position is allocated, upon certification of the appointing authority that the person to be employed has served satisfactorily in a comparable position within or without the commonwealth for a period of time equivalent to the period required by the salary schedule had such service been entirely in the service of the county, provided, that said board shall not approve the recruitment of any person at a rate above the minimum of the grade if such proposed employee has been in the service of any county within a twelve month period prior to the date of the proposed employment.

(4B) Said board may permit the recruitment of all professional vocational and technical personnel, including teachers, administrators and supervisory staff of the Bristol county agricultural school, the Essex agricultural and technical institute and the Norfolk county agricultural school, at a rate above the minimum but within the grade at which the position is allocated, upon certification of the appointing authority that the person to be employed has served satisfactorily in a comparable position within or without the commonwealth for a period of time equivalent to the period required by the salary schedule had such service been entirely in the service of the county.

(5) When an employee is initially placed in the salary schedule, or is advanced in his job group, or is transferred, reallocated or promoted to a new job group, such employee, for subsequent step-rate increases, shall be credited with the number of years of service that corresponds to his job group and rate in the salary schedule.

(6) Whenever an employee receives a promotion to a position in a higher job group, his rate shall be the next higher rate in said higher job group, or the second next higher rate therein if such new salary rate would result in an increase of salary smaller in amount than the salary increment for such higher job group.

(7) An employee who is demoted to a position in a lower job group shall receive the salary to which his period of service would entitle him if his service had been rendered in the lower group, but not less than the employee would have been entitled to had his service been continuously in the lower group.

(8) Rates of compensation in the salary schedule are for work hours as provided by the rules or regulations of said board; provided, however, that such rules or regulations shall establish the circumstances under which the county commissioners may relieve an employee or employees of such hours of work without reduction in salary.

(9) An employee serving on a part-time basis as certified by the appointing authority shall be entitled to the provisions of this chapter in the proportion that his service bears to full-time service.