1965 Dodge Dart Door Locks...

Not everyone is the "do it yorselfer" when it comes to those tiny springs and such.
If your willing to try, there is a guy parting some early Chrysler products (furys and newports). So rather than deal with worn out door/ignition keys and locks, grab a trunk lock and key. Build you door and ignition lock cylinders to that key which has much less wear. Any locksmith should be able to help.