With respect to each employee to whom both sections 6 and 7(f) of the Act apply, the employer shall maintain and preserve payroll or other records containing all the information and data required by Sec. 516.2(a) except paragraphs (a) (8) and (9), and, in addition, the following:
(a) Total weekly guaranteed earnings,
(b) Total weekly compensation in excess of weekly guaranty,
(c) A copy of the bona fide individual contract or the agreement made as a result of collective bargaining by representatives of employees, or where such contract or agreement is not in writing, a written memorandum summarizing its terms.