The Continental Mill along the Androscoggin River in Lewiston is seen in the aerial photo from 2019. Sun Journal file photo LEWISTON — The Historic Preservation Review Board on Thursday afternoon unanimously approved a Certificate of Appropriateness for a potential new development at the Continental Mill: Picker House Lofts. Szanton Monks Properties is behind the 72-unit mixed income housing project at 2 Cedar St. and has a purchase and sale agreement in place with Chinburg Properties for 76,500-square feet of the massive mill, according to board filings. “Our business model is to wait until we are ready to start construction to close on a piece of property,” Szanton’s Amy Cullen said Thursday.