Work to convert the former Main Street Inn site into an overflow parking area for patrons of Hollywood Slots at Bangor is winding down. “It’s slated to be completed early next week,” Amy Kenney, manager of marketing and public relations at Hollywood Slots, said Thursday. The site has been excavated and now is being graded and paved. Lighting will be added, Kenney said. Since the temporary racino opened last November in the former Miller’s Restaurant on Main Street, where parking is limited, Hollywood Slots has been leasing city-owned land at Bass Park as extra parking space. It bought a shuttle bus to carry patrons between the lot and the racino. Penn National Gaming Inc., the racino’ s parent corporation, acquired the Main Street Inn and nearby Holiday Inn-Civic Center as the site for its proposed $72 million permanent gambling complex, which will house up to 1,500 slot machines, restaurant and retail space and include a multilevel parking garage.