In the event workmen or laborers qualified under the provisions of Section 31-5-17 are not available, then the contractor, officer, superintendent, agent, or person in charge of such work shall notify in writing the mayor of the city in which said work is being done, the president of the board of supervisors of the county in which said work is being done, the Governor where said work is being done for the State of Mississippi, and the president, chairman, or executive officer of such board, city commission, or governmental agency for which said work is being done, of such fact. Unless the mayor, Governor, president, executive officer, or chairman aforesaid, as the case may be, shall forthwith supply such contractor, officer, superintendent, agent, or person in charge of said works with the satisfactory workmen or laborers needed, said contractor, officer, superintendent, agent, or person shall be authorized to employ workmen or laborers who are not qualified under the provisions of Section 31-5-17 to make up the deficiency. Nothing herein shall be construed to prevent the State of Mississippi, any county, municipality, board, or commission from placing or letting any contract for the erection or construction of any public building or public work in the open market, or soliciting bids from persons, firms, or corporations without the State of Mississippi. Any person, persons, firm, or corporation from without the State of Mississippi that may obtain such contracts for public buildings or public works shall comply with the provisions of Section 31-5-17 upon undertaking the said contract or work.