The minutes of the proceedings of the joint board and the assessment roll as finally settled by such board shall be made up in as many counterparts as there are counties joining as aforesaid, and shall be signed by the chair and clerk of said board, and one of said counterparts so signed shall be filed by said clerk with the clerk of the board of county commissioners of each of said counties, and any appeals and subsequent proceedings under RCW 88.32.090 to 88.32.170, inclusive, as far as relates to real estate in any individual county, shall be as nearly as may be the same as if the local improvement district and bond issue concerned that county only.