It's not quite in Philly, but is close enough to drive: Flute Pro Shop
in Wilmington, Delaware. David Kee is the repair tech there. He is a master repair technician who has trained at the Muramatsu Shop in Japan and is usually in the Muramatsu booth at the National Flute Association conventions repairing flutes at the show.
Although not in your neighborhood, but highly recommended is Adam Pettry
at Pettry Flute & Piccolo Service
in the Atlanta area. He's a regular here on this board.