Nothing in this act shall be construed to alter or abrogate any existing fire protection contract between any city and county or any city and any township, but all such contracts may be, by mutual agreement, terminated at the end of the budget year in which such termination is made effective. All funds of the township or county in process of collection (and delinquent taxes), and funds in the hands of the county treasurer shall be by him credited to the funds of the successor fire district or districts as may be organized by virtue of this act.