Disc brake conversion wheel hub sizing

I've been doing a bunch of googling and it really looks like those hubs are not made or available anymore which is a bummer. Yup, I've been reading posts on how to separate the hub from the drum, doesn't seem to bad.
It's just, what do you do when the hub eventually goes bad?

Unless it gets damaged in some way, I'm not sure it ever go bad. The bearings and races are replaceable and are available.