This afternoon Jane had the same problem her key bow (what I think is the technical term for the bit that doesn’t go into the lock) as I had last November. The original gave way and she was struggling to get in the door. Fortunately I was in and also, because it is a duplicate of my key, I had the 3D model ready to fire up as soon as she had picked the colour she wanted (a metallic “brass” silk PLA). It did feel a bit tight fitting the shank but a quick blast of the plastic with a hot air gun allowed me to press it in flush and then I continued printing to seal it in place.

My one has held up almost a year with no sign of failing yet so this should keep her going a good while yet.