When towns are incorporated, the assessors of the town shall return to the county commissioners of their county the original valuation first taken in their towns, on or before the 15th day of May following the town's incorporation. The county commissioners shall examine and correct this valuation and return a copy of the valuation to the Treasurer of State. This corrected valuation shall be the basis of state and county taxes in the same manner as the valuations of plantations under section 7008.   [PL 1987, c. 737, Pt. A, §2 (NEW); PL 1987, c. 737, Pt. C, §106 (NEW); PL 1989, c. 6 (AMD); PL 1989, c. 9, §2 (AMD); PL 1989, c. 104, Pt. C, §§8, 10 (AMD).]