The Commission is authorized, for a period not to extend beyond five years after August 4, 1955, in the case of Oak Ridge and Richland, or, in the case of Los Alamos, not to extend beyond five years after the date it is included within this chapter, to cooperate with and assist the residents of the community in preparation for and establishment of local self-government and in the transfer of municipal installations and responsibilities to local entities. Such assistance may include payment of any amounts reasonably necessary to meet expenses incident to the establishment and organization of a city government and other local entities at the community, until such time as the municipal installations are transferred in accordance with the provisions of this subchapter.