(a) The surveyors or professional engineers in civil engineering composing such commission shall each receive such compensation as the court shall fix for the time necessarily spent in the discharge of their duties and, in addition thereto, shall be reimbursed the necessary expenses incurred by them respectively while engaged upon the work of such commission.

(b) The commission may employ such assistants as the court shall allow, at a compensation to be fixed by the court, and such assistants shall be reimbursed the actual necessary expenses incurred by them respectively while employed by such commission.

(c) The necessary expenses of advertising the meeting of the commissioners, as hereinafter provided, and in procuring and setting the monuments needful to mark in a permanent manner such county line, the expenses of the commission and its assistants and all other expenses necessarily incurred, shall be paid by the interested counties jointly in equal parts, upon presentation of properly itemized bills duly verified by affidavit of the person claiming payment or some one on his behalf.