The buildings and the hardware
The building stock in this part of Philadelphia affects the hardware we see. Many doors are older wood or metal door slabs fitted into masonry openings, and owners have often layered hardware over time: an old mortise lock beside a modern deadbolt, or a surface-mounted latch added to reinforce a worn frame. There are also multiunit apartment entries and street-level storefronts with commercial-grade cylindrical locks, panic hardware on exits, and curbside mailboxes on older posts. Those differences change the job: tighter tolerances on older doors, custom adapters for nonstandard hardware, and attention to thresholds and strike plates to get a reliable operation.