The buildings and the hardware
The housing stock in this part of Chester County affects the hardware we see. Older homes often keep original mortise locks or rim locks; those can be serviced or fitted with compatible replacements but sometimes need conversion to standard bored locks. There are also duplexes and small apartment buildings with common-area hardware that has seen heavy use; that shows up as worn strike plates, loose flush bolts, or keys that no longer cut cleanly. Storefronts and professional suites usually have commercial-grade cylindrical locks or exit devices; that changes the parts and techniques we bring on a call, especially for keyed-alike systems.