Had a customer with a misbehaving Baldwin mortise lock on their houseboat, I told them about Baldwin’s lifetime mechanical warranty and how they could get a replacement for free but they were not the original purchaser of the lock. Rather than buy a replacement for $800-1000, they asked about other options.
These people had a worn out hub so their knob didn’t retract the latch, they could get locked inside or outside. I proposed making sure the Baldwin no longer locked and using a deadbolt above it, using a ballcatch to hold the door shut. You could use a magnet to hold the door shut instead.
The trick was to replace the strike plate (in this case already missing anyway) with a blank plate. Then one can open or shut the door by pulling on the knob. When the door is pulled shut the springloaded ball catch goes into an indent on the doorframe. This was an especially nice solution because the door was a custom made mahogany.