Section 69A. Any city or town which maintains or operates a municipal lighting plant which includes a gas plant may purchase, sell and distribute natural gas, and the provisions of sections thirty-four to sixty-nine, inclusive, so far as apt, shall apply to the purchase, sale and distribution by such city or town of natural gas. Every such city or town purchasing, selling and distributing natural gas shall have all the powers and be subject to all the liabilities of said sections, including the authority to borrow money for the establishment, extension or enlargement of a plant and providing facilities for the purchase, sale and distribution of natural gas.