Chapter VIII of the Laws and Ordinances of the City of Bangor of September 24, 1974, as amended; Chapter XI of the Laws and Ordinances of the City of Bangor of September 13, 1971, as amended; and Chapter XII of the Laws and Ordinances of the City of Bangor of February 19, 1959, as amended, all formerly existing, are hereby repealed, except that they shall remain in full force and effect for the trial and punishment of all past violations of them and for recovery of penalties and forfeitures already incurred.