The Station Lofts apartment complex at 124 Montello St. in downtown Brockton had its official opening last week even though it has been fully occupied since December. The historic industrial building that once housed Geo. Knight & Co. Inc., a manufacturer of shoes and heat press machinery, and the Stall & Dean Co., believed to have created the first catcher’s mitt, was converted and renovated by the Cambridge-based Capstone Communities LLC. The site now includes 25 mixed-income residential apartments, surface and garage parking, a fitness center, storage, and onsite management. In a statement, Mayor Bill Carpenter characterized the project as “a cornerstone” of the rebirth of downtown Brockton. “We hope this project serves as an inspiration for others to invest in the city,” Carpenter said. The project received $1.5 million in state Department of Housing and Community Development housing subsidies and another $495,348 in federal and state low-income housing tax credits. Capstone principal Jason Korb said the successful public-private effort preserves a piece of Brockton’s significant manufacturing history and transforms the building into high-quality housing for “hard-working individuals and families.”