Such withdrawal or dissolution shall not impair the obligation of the withdrawing town or the district to the holders of any bonds or other outstanding indebtedness issued prior to withdrawal or dissolution under authority of this part, including any responsibilities or financial obligations related to a school building project pursuant to chapter 173. The regional board of education and the board of education of the town or towns involved may make agreements for the payment of money to or from the district and said towns in accordance with the final plan of withdrawal, except any such agreement or final plan of withdrawal shall not relieve a withdrawing town from its responsibilities or financial obligations related to a school building project pursuant to chapter 173.