The person repairing an old model is caring for an earlier version of their attention.

Keeping an old thing running is partly about the thing and partly about who you were when it mattered. The model, the bike, the radio holds a period of your life when you had time and interest to spend on it, and the repair is a way of staying in contact with that attention rather than letting it lapse. It looks like nostalgia from outside and feels like continuity from inside. There is nothing sentimental about wanting to remain the same person a while longer.

If something old is waiting for you, give it an hour without justifying the hour. The point is the contact, not the finished object.