The 1935 Project

For the past 4.5 years now we have been working on our home that was constructed in 1935. It has been fun but a lot of work, we still are working on the exterior, new fence, paint, and the list never stops.
Anyways the picture is of one of the door knobs from inside the house. I was looking at the door knob wondering if in 73 years, the doors that we install in the homes that we are building will still work. I doubt it.