papers on which it is based on the
owners and mortgagees of record and lienors. If any such owner,
mortgagee or lienor cannot with due diligence be served personally
within the city where the property is located and within the time fixed
in such order, then service may be made on such persons by posting a
copy thereof in a conspicuous place on the premises where the nuisance
exists, and by sending a copy thereof by registered mail, return receipt
requested, to the owner at the last address registered by him with the
department, or in the absence of such registration, to the address set
forth in the last recorded deed with respect to said premises, or, in
the case of a mortgagee or lienor, to the address set forth in the
recorded mortgage or lien and by publication in a newspaper of general
circulation in the county where such premises are located, which
newspaper, if there is an official law paper for such county, shall be
such official law paper. Service shall be deemed complete on filing
proof of service thereof in the office of the clerk of the court in
which such application is made.