In the case of evaluation, assessment, collection, apportionment, and any other allied power or duty relating to taxes in connection with the city or town, the action shall be performed by the county, county legislative authority, or county officer or board of the county for that area of the city or town which is located within the respective county, and all materials, information, and other data and all moneys collected shall be submitted to the proper officer of the county of that part of the city or town in which the largest number of inhabitants reside. Any power which may be or duty which shall be performed in connection therewith shall be performed by the county, county legislative authority, officer, or board receiving such as though only a city or town in a single county were concerned. All moneys collected from such area constituting a part of such city or town that should be paid to such city or town shall be delivered to the treasurer thereof, and all other materials, information, or data relating to the city or town shall be submitted to the appropriate city or town officials.

Any costs or expenses incurred under this section shall be borne proportionately by each county involved.