Sink plug knob

This goes into the "Honey-I-bought-a-thousand-dollar-machine-to-do-a-fifty-cent-repair" department.
The knob of our kitchen sink plug broke off months ago and we could not find another plug that would fit. I tried a couple of unsuccessful fixes and then I thought (light bulb over my head!), why don't I make something useful with my MakerBot?
It took three builds to get one that would fit. First, the hole was a bit small for the base, then the inside walls were bulging in a bit so that it was h